Korea Tenders - 24 March 2026 (Page 4 of 22)

4,328 tenders published in Korea on 24 March 2026.

Tender Impulse is your trusted global tender website and tender aggregator, offering access to tens of thousands of tenders from over 190 countries. On this page, explore all government tenders, business tenders, and e-tenders published in Korea on 24 March 2026, across industries like Park Management, Management Consultancy, IT-Software, Sports Goods, Toys & Recreation, Environment & Waste Management, Agriculture, Farming & Forestry, Laboratory & Scientific Instruments, Infrastructure and construction, Electrical Equipment & Lighting, Furniture & Furnishings, Defence, Energy, Textiles, Clothing & Leather, Banking, Financial & Insurance, Logistics, Transportation & Mobility, Oil and Gas, Healthcare & Medical, Telecom, Government & Community Services, Meters, Education & Training, Food & Beverages, Repair, Maintenance & Installation, Adhesive & Labels, Industrial Machinery & Equipment, Research & Development, Transportation Ports & Waterways.

This is page 4 of 22 for tenders published in Korea on 24 March 2026.

Why Choose Tender Impulse for Korea?

  • Access a curated list of tender notices from official sources, including ministries, PSUs, and local procurement authorities.
  • Daily updates of world tenders covering Korea and beyond.
  • Tailored listings for sectors like Park Management, Management Consultancy, IT-Software, Sports Goods, Toys & Recreation, Environment & Waste Management, Agriculture, Farming & Forestry, Laboratory & Scientific Instruments, Infrastructure and construction, Electrical Equipment & Lighting, Furniture & Furnishings, Defence, Energy, Textiles, Clothing & Leather, Banking, Financial & Insurance, Logistics, Transportation & Mobility, Oil and Gas, Healthcare & Medical, Telecom, Government & Community Services, Meters, Education & Training, Food & Beverages, Repair, Maintenance & Installation, Adhesive & Labels, Industrial Machinery & Equipment, Research & Development, Transportation Ports & Waterways, including projects in EPC, defence, and infrastructure.
  • Easy filters to sort tenders by publish date, keywords, CPV codes, or authority name.

Get Started with Full Access

With a simple free live demo, gain access to tender details, bidding documents, authority contacts, and real-time updates from Korea.

12044760 Landscaping work for the Cultural Happy Industrial Complex Creation Project Deadline27 Mar 2026 12044761 Online company review sharing service service in 2026 Deadline23 Mar 2026 12044762 Operation of joint workshop on child protection system in 2026 Deadline04 May 2026 12044763 IDC integrated security solution purchase bid Deadline07 Apr 2026 12044764 Hosted an academic conference at the Catholic Holy Site, Wanju Chonam Iseongji. Deadline25 Mar 2026 12044765 2026 Spring Afforestation Project (No. 1) Deadline06 Apr 2026 12044766 Sejong Cyber ​​University’s selection as a comprehensive advertising agency for the 2026 school year Deadline07 Apr 2026 12044767 Hyoja Jugong - Bidding notice for selection of asbestos dismantling, removal and treatment partner company Deadline31 Mar 2026 12044768 Renewal of power system analysis tool (PSS/E) license in 2026 (right purchase) Deadline27 Mar 2026 12044769 2026 rice seedling supply support project (unit price contract, private bidding agency) Deadline27 Mar 2026 12044770 Specimen pretreatment system Deadline07 Apr 2026 12044771 Spring 2026 Samsung District drainage ditch dredging project Deadline23 Mar 2026 12044772 Godeok International Planning District Phase 3 Section Soil Pollution Cleanup Service Deadline31 Mar 2026 12044773 Establishment service for nightscape lighting guidelines for the 3rd new city Deadline03 Apr 2026 12044774 2026 Incheon Regional Headquarters Construction Rental Housing Comprehensive Promotion Service Deadline03 Apr 2026 12044775 Office old wall replacement work Deadline24 Mar 2026 12044776 Daegu Environmental Love Promotion Education Center dismantling design service Deadline24 Mar 2026 12044777 Order for pavement restoration and water pipe maintenance work in Donggok district in 2026 Deadline23 Mar 2026 12044778 Farm road paving work in 1211 Saje-ri, Heungeop-myeon Deadline23 Mar 2026 12044779 Samdal 2-ri Village Unit Specialized Development Project Construction Detailed Design Service Deadline23 Mar 2026 12044780 Namsan Park forest road dangerous tree maintenance work Deadline23 Mar 2026 12044781 Waterway maintenance work for Gaepo 4-2 branch line and 2 other locations Deadline23 Mar 2026 12044782 Daedong Clear Water Circulation Center Centrifugal Dehydrator Replacement Project Purchase of government-supplied materials (chemical injection machine) Deadline24 Mar 2026 12044783 Roadside green space expansion planting work Deadline23 Mar 2026 12044784 Buk-gu District drainage ditch dredging work in preparation for the 2026 farming season Deadline23 Mar 2026 12044785 Tancheon Center sludge drying facility storage tank (silo) unit 1 dredging work Deadline23 Mar 2026 12044786 Goseong-gun Chodo Port Fishing Village New Deal Project Facility Construction (Construction) Combustible Waste Disposal Service Deadline23 Mar 2026 12044787 Pyeongdong district drainage ditch dredging work in preparation for the 2026 farming season Deadline23 Mar 2026 12044790 Technical diagnosis service for village sewerage area in Nam-gu, Gwangju (Yanggwa Boksu district) Deadline24 Mar 2026 12044791 「SIWW 2026」 Singapore International Water Expo Arisu promotional booth production and installation service Deadline23 Mar 2026 12044792 2026 Chunghwa-myeon basic living base creation project interior product installation service Deadline23 Mar 2026 12044793 Automatic control system improvement work including machine room at King Sejong History and Culture Museum Deadline23 Mar 2026 12044794 Cover to prevent foreign substances from entering, cover and 6 other types Deadline23 Mar 2026 12044795 Dongpyeong Middle School School Space Innovation Dadam Project Design Service Deadline23 Mar 2026 12044797 Paving work on the cultivation road at 385-10 Pandae-ri, Jijeong-myeon Deadline23 Mar 2026 12044800 345kV power cable (PE, 1C, 2000SQ) 511M and accessory materials (345kV Shinnamwon S/S) Deadline01 Apr 2026 12044802 154kV power cable (PE, 1C, 2000SQ) 1,700M and auxiliary materials (North Chungju S/S, etc.) Deadline01 Apr 2026 12044803 154kV porcelain tube replacement polymer tube (EBA, 1200㎟) [Gyeongbuk Headquarters (Kolon TL)] Deadline31 Mar 2026 12044804 8,065M of 0.6/1kv cable (F-CV 1C×50㎟) and 5 other types (HVDC Construction Headquarters) Deadline31 Mar 2026 12044844 Production and purchase of Korea Expressway Corporation auxiliary work uniforms in 2026 Deadline30 Mar 2026 12044846 Purchase of engineering SW MIDAS technology license in 2026 Deadline27 Mar 2026 12045148 Construction service for rural tourism promotional content in 2026 Deadline13 Apr 2026 12045153 Pangyo Stream River Maintenance Work Deadline27 Mar 2026 12045157 Sign up for group accident insurance and workers’ compensation liability insurance for repair facility inspectors in 2026 Deadline30 Mar 2026 12045161 Vehicle rental service in accordance with the operation of the 2026 Starry Forest Visiting Experience Program Deadline27 Mar 2026 12045166 Management indicator measurement and evaluation service for urban forests in Gumi City, etc. Deadline27 Mar 2026 12045168 Gobong reservoir C, D inflow and outflow valve cable replacement work Deadline27 Mar 2026 12045173 Selected as a banner advertising agency for the application submission site for new students for the 2027 school year Deadline03 Apr 2026 12045184 Service for establishing the 5th Jeonbuk Special Self-Governing Province’s transportation convenience improvement plan and transportation safety basic plan Deadline03 Apr 2026 12045185 2026 Cheoin-gu Public Health Center quarantine and disinfection service (Yeonmu 14 area) Deadline27 Mar 2026 12045189 Naechon access road rainwater pipe installation work Deadline27 Mar 2026 12045201 2026 Cheoin-gu Public Health Center quarantine and disinfection service (Yeonmu 13 area) Deadline27 Mar 2026 12045207 2026 Cheoin-gu Public Health Center quarantine and disinfection service (Yeonmu 12 area) Deadline27 Mar 2026 12045208 2026 Gyeonggi Social Economy Expo Operation Service Deadline14 Apr 2026 12045210 Purchase of 2 types including INFUSION PUMP Deadline31 Mar 2026 12045212 Printing of Korean language textbooks for children for overseas Koreans in 2026 Deadline03 Apr 2026 12045213 2026 Cheoin-gu Public Health Center quarantine and disinfection service (Yeonmu 11 area) Deadline27 Mar 2026 12045216 Seoul Forest old communication cable replacement work Deadline23 Mar 2026 12045310 26-Prevention-11 Unit 00 shower room and military boot washing area repair work Deadline27 Mar 2026 12045311 Unit 00 transport unit water supply pipe replacement work (Total-4) Deadline27 Mar 2026 12045312 Haewadal Daycare Center heating and cooling facility improvement project (disaster prevention-mechanical) Deadline27 Mar 2026 12045313 Research service to maintain fuel cleanliness and trace the source of pollution Deadline14 Apr 2026 12045314 26 years of weeding service - D area Deadline27 Mar 2026 12045315 26 years of weeding service - Area C Deadline27 Mar 2026 12045316 26 years of weeding service - Area A Deadline27 Mar 2026 12045317 Ice water purifier rental service for 26~29 years Deadline27 Mar 2026 12045318 Design service for 5 cases including replacement of old water supply facilities in Unit 26-M-00 (C005) Deadline31 Mar 2026 12045320 Rental car rental service for facilities in 2026 Deadline27 Mar 2026 12045321 '26 Commercial blanket laundry consignment service Deadline27 Mar 2026 12045322 buy gun bearings Deadline31 Mar 2026 12045323 Manufacture of necessary materials for UH-60 helicopter flame detector inspection device Deadline14 Apr 2026 12045324 MW RF equipment function improvement project Deadline27 Mar 2026 12045325 Purchase of 11 types of K9 self-propelled gun bolts, machines, etc. Deadline31 Mar 2026 12045326 Purchase of 2 types including K77 command vehicle indicator Deadline31 Mar 2026 12045327 K77지휘차 계전기, 전자자기식 등 1종 구매 Deadline31 Mar 2026 12045328 26 years of equipment covers (mobility, guns) Deadline31 Mar 2026 12045329 26 years of Biho artillery system repair parts (manufacturing) Deadline02 Apr 2026 12045330 26-011 Residential facility sink installation delivery Deadline27 Mar 2026 12045331 Announcement on submission of small number of quotations (proposal to purchase drinking water quality team equipment in 2026 (multi-item water quality meter, rotary shaker)) Deadline30 Mar 2026 12045349 [Urgent] 2026 Daegu Gyeongbuk Headquarters Central Separator Improvement Construction Deadline30 Mar 2026 12045350 Purchase of materials (tree supports) for landscaping work between Hamyang and Hapcheon Deadline31 Mar 2026 12045351 3 sets of unmanned security system main materials (Jincheon S/S, etc.) - Chungbuk Headquarters Deadline23 Apr 2026 12045352 High-intensity aviation obstacle lights (3 types, including B-1) - Daejeon Sejong Chungnam Headquarters (region limited) Deadline07 May 2026 12045353 SA mixed operation system, SA operation device and 3 other types (Seongsan SS) Deadline31 Mar 2026 12045354 HTACSR-AW(480SQ) 602,490M (HVDC 2 tools, etc.) Deadline07 May 2026 12045488 Announcement on submission of quotation for small amount of milk meals for Haenam High School school meals in 2026 Deadline30 Mar 2026 12045489 Notice on submission of small quantity quotation for purchasing milk for school meals in 2026 Deadline30 Mar 2026 12045490 Notice on submission of small amount quotation for milk purchase for Changpyeong High School school meals in 2026 Deadline30 Mar 2026 12045491 Platform surveillance monitor installation work (3 stations, 6 meals) Deadline30 Mar 2026 12045492 Notice on submission of quotation for small quantity (unit price) for purchasing milk for school meals in 2026 Deadline26 Mar 2026 12046158 2026 Main building air conditioner installation work (electrical) Deadline27 Mar 2026 12046168 Purchase and installation of stage lighting equipment at Songdo Culture Maru Performance Hall Deadline03 Apr 2026 12046209 Forest survey service for Samdal 2-ri village-level specialized development project Deadline23 Mar 2026 12046213 Implementation of quarantine and disinfection service in Region 1 in 2026 Deadline27 Mar 2026 12046255 2026 local tax information system operation management supervision service Deadline07 Apr 2026 12046256 Generator material safety certificate sticker and 19 other types Deadline23 Mar 2026 12046257 Data storage large capacity storage (Ts-h2490FU-7302P) Deadline07 Apr 2026 12046258 2026 Jangsu-gun Economic Tree Afforestation Project (Jangsu District 2) Veterinary Contract Notice Deadline27 Mar 2026 12046259 Purchase of LOW TEMPERATURE STERILIZER at Kyung Hee University Hospital Deadline07 Apr 2026 12046260 2026 Small-scale themed educational trip for first graders Deadline06 Apr 2026 12046261 Dust mask and 6 other types Deadline24 Mar 2026 12046262 Jangsu Dongchon-ri Ancient Tomb Group No. 16 Restoration Maintenance Project Negotiated Contract Notice Deadline27 Mar 2026 12046263 Replacement work for old elevators in Gyeongsan Campus Deadline07 Apr 2026 12046264 Duseo Daegokcheon (Yuchon Village) river maintenance work Deadline31 Mar 2026 12046265 Landmark construction project basic concept and feasibility review service Deadline30 Mar 2026 12046266 Selected as an electric vehicle charging facility company Deadline30 Mar 2026 12046267 Landscaping work within the complex Deadline30 Mar 2026 12046268 Re-announcement of bid for selection of cadastral survey service provider Deadline30 Mar 2026 12046269 Gangjeong Village sauna facility basic concept and feasibility study service Deadline07 Apr 2026 12046270 2026 water supply and water leak recovery unit cost construction (long-term continuous) construction waste disposal service Deadline27 Mar 2026 12046271 Seoul National University Hospital [Other research costs] Single cell automatic library production machine 1SYS Deadline07 Apr 2026 12046272 (Bidding agency) Air purifier and air sterilizer maintenance service per senior citizen Deadline27 Mar 2026 12046273 Announcement on the 2026 Shanxi (Bongxi) District Living Environment Improvement Project Negotiated Contract Deadline27 Mar 2026 12046275 Investment company equity management legal advisory service contract Deadline07 Apr 2026 12046276 [Re-announcement] Dankook University selected as a comprehensive advertising agency Deadline07 Apr 2026 12046277 Mongolian public rental housing operation management and resident-specific defect/maintenance management framework implementation and guideline proposal service Deadline07 Apr 2026 12046278 Old street light pole maintenance work in Shinho-dong area Deadline27 Mar 2026 12046279 Jangsu Medical Center Old Building Roof and Wall Repair Guidance Notice on Negotiated Contract Deadline27 Mar 2026 12046280 Waste disposal service for road resurfacing and maintenance work (Section 3) in the district in 2026 Deadline27 Mar 2026 12046281 Deokam Village small-scale water development project Deadline27 Mar 2026 12046282 Bicycle insurance subscription service for Buan-gun residents in 2026 Deadline27 Mar 2026 12046283 Beop-myeon maintenance work near Eonyang Reservoir on City Line 9 in Sadeung-myeon Deadline27 Mar 2026 12046284 Samnam Gongam Stream River Maintenance Work Deadline31 Mar 2026 12046285 2026 Okcheon-gun slate processing support project (Area 8, Gunseo-myeon, Gunbuk-myeon) [Bidding agency] Deadline27 Mar 2026 12046286 #Waste disposal service for the Harmony Center construction project Deadline27 Mar 2026 12046287 2026 Supervision service for young tree care at Jangan Mountain Seondo Forest Management Complex Deadline27 Mar 2026 12046288 Geumgang Estuary Bank Public Parking Lot Tree Battery Construction Deadline27 Mar 2026 12046289 2026 Buk-i Jukcheong district mountain stream conservation project Deadline27 Mar 2026 12046290 Pulmonary toxicity evaluation service for ITO using a single intratracheal injection rat model Deadline03 Apr 2026 12046291 Consignment service for the operation of the 5th Gongju Future Agriculture Academy Deadline03 Apr 2026 12046292 Green zone management construction (Sunae-dong) Deadline27 Mar 2026 12046293 2026 Sehwa High School first year out-of-province topic exploration activity (school trip) consignment service [Urgent] Deadline03 Apr 2026 12046294 2026 Buan-gun organic sludge treatment service (unit price contract) Deadline27 Mar 2026 12046295 (Re-announcement) (Junior College Innovation Support Project) Purchase of cultural heritage preservation technology and equipment (14 types including wireless transmitters and rece Deadline30 Mar 2026 12046296 Research on identifying standards for regulatory targets for digital facilities at nuclear facilities and differentiating regulations based on importance Deadline06 Apr 2026 12046297 Seongdong-gu sewerage field construction project management service (long-term continuous) Deadline17 Apr 2026 12046298 (Gogo-2) 「Preparation of electronic drawings of remains from excavation surveys of major ruins around the world」service Deadline24 Mar 2026 12046299 2026 International Survey Report Quality Analysis Project Deadline03 Apr 2026 12046300 Dangjin forklift (10132980) repair Deadline25 Mar 2026 12046301 2026 Dongducheon Waterworks Governor’s water facility cleaning service Deadline30 Mar 2026 12046353 2026 KAIST Idea Hackathon Overseas Training Deadline07 Apr 2026 12046354 Purchase of rice mechanical transplanting soil mat in 2026 Deadline24 Mar 2026 12046355 Selected as a food ingredient company for the Senior Citizens’ Restaurant at Hwangsong Senior Welfare Center in 2026 Deadline07 Apr 2026 12046356 Sign up for rental agricultural machinery insurance according to the operation of the agricultural machinery rental business Deadline27 Mar 2026 12046357 2026 Daegu Cheongna Middle School school uniform (summer uniform, winter uniform)) School-sponsored purchase bid notice Deadline27 Mar 2026 12046358 Purchase Infiniband Switch (Mellanox QM8790 Inifindband Switch) Deadline07 Apr 2026 12046359 2026 Electrical safety management agency for private vehicle electric equipment at the discharge and drainage plant Deadline23 Mar 2026 12046360 Agency service for regular safety inspection of government building in 2026 Deadline23 Mar 2026 12046362 2026 Sungeui Girls’ Middle School 3rd grade training activity service provider (room and board) bid notice Deadline01 Apr 2026 12046364 120Dasan Call Foundation 2026 Purchase of counseling headquarters computer consumables (headset, amplifier) Deadline24 Mar 2026 12046365 2026 Daegu branch air pollutant consignment measurement service Deadline31 Mar 2026 12046367 2026 Consignment service for psychological counseling for popular culture artists Deadline04 May 2026 12046369 Safety valve replacement work for boiler steam Deadline25 Mar 2026 12046371 2026 Korea National University of Education Apostolic Education Center 1st Semester (2nd Session) Notice on Submission of Small Quantity Quotation for Purchase of School Food Produ Deadline27 Mar 2026 12046372 Research service to survey the actual status of underwater leisure activities for systematic safety management Deadline03 Apr 2026 12046373 Marine waste disposal service in 2026 (1st) Deadline31 Mar 2026 12046374 Announcement of bidding for school-sponsored purchase of Shinyong Middle School gym uniforms for the 2026 school year [2nd stage (simultaneous specifications and prices) bidding] Deadline03 Apr 2026 12046375 Establishment of basic plan and feasibility study for the 7 major projects of the West Coast Association Deadline07 Apr 2026 12046376 Disaster impact review of the western metropolitan express railway construction project Deadline31 Mar 2026 12046377 2026 Sewage treatment plant flow meter inspection and calibration (for gas) Deadline27 Mar 2026 12046378 Purchasing plasma focused ion beam scanning electron microscope (PFIB) parts Deadline31 Mar 2026 12046379 (Training) Manufactured and supplied drone jamming guns to the former Mobile Unit Deadline30 Mar 2026 12046380 Purchase of Donghae Units 1 and 2 coal system dust collection facility bag filters Deadline30 Mar 2026 12046381 Purchase firefighting clothing and safety shoes for the Forest Disaster Response Team in 2026. Deadline27 Mar 2026 12046383 Bicycle road convenience facility (rest area) improvement work Deadline27 Mar 2026 12046384 April 2026 Announcement of submission of quotation for joint purchase of school supplies (corrosion) for Yongam Elementary School and 1 school (Yongam Elementary School, Cheongju H Deadline27 Mar 2026 12046385 Safety inspection service for agricultural products shipped to local food direct stores in 2026 Deadline27 Mar 2026 12046386 Yuhan University Student Dormitory New Construction Supervision Service (Electrical) Bidding Notice Deadline07 Apr 2026 12046387 Gwanmaedo Gomsol Luxury Beach Development Project General Ocean Use Consultation Service Deadline27 Mar 2026 12046388 Purchase and installation of smart road heating system in 2 locations including Nakseongdae Station Road Deadline26 Mar 2026 12046389 Sokcho City Urban Flood Response Project (Phase 1) Electrical and Instrumentation Control Construction Deadline27 Mar 2026 12046390 Scaffolding installation for replacement and maintenance of Unit 3 TBN UnitHeater Deadline31 Mar 2026 12046391 2026 Sewage treatment plant flow meter inspection and calibration (for liquid) Deadline27 Mar 2026 12046392 Eddy covariance system_PA202600111 Deadline30 Mar 2026 12046393 2026 online export joint logistics operation support performance service Deadline03 Apr 2026 12046394 Gaheung Intersection Lamp Old Street Light Electrical Circuit Replacement and Lighting Fixture Replacement Work Deadline27 Mar 2026 12046395 2026 Shin Jeong-ho Kids Garden and Haneulgil Forest Wood Waste Disposal Service Deadline27 Mar 2026 12046396 Muju Cultural Center remodeling project (construction) Deadline27 Mar 2026 12046397 Detailed design service for Gokseong-gun disaster risk river maintenance project (overall and 1st installment) Deadline27 Mar 2026 12046398 Research on international shipping greenhouse gas levy management system and operation plan Deadline03 Apr 2026 12046399 Green Zone Management Construction (Daejang District) Deadline27 Mar 2026 12046400 Survey on the actual situation of household goods businesses that comply with safety standards and derive improvement measures Deadline07 Apr 2026 12046401 Gyeongsangnam-do 2nd architectural asset promotion implementation plan establishment service Deadline31 Mar 2026 12046402 Fabrication and installation of carbonizer Deadline02 Apr 2026 12046403 Announcement of guidance on submission of execution plan and project performance evaluation report (integrated construction project management service, including supervising author Deadline07 Apr 2026 12046404 [Printed matter] Unit price contract for 4 items including RFID labels (groups 2 and 3) Deadline07 Apr 2026 12046405 Bidding notice for selection of print production company related to new student recruitment Deadline07 Apr 2026 12046406 Construction of a base-type Neulbom Center and mechanical equipment construction Deadline27 Mar 2026 12046407 Public Home Shopping 2026 Recruitment Agency Service Deadline03 Apr 2026 12046408 Production of Korean ARPA-H project promotional content and dissemination of results Deadline07 Apr 2026 12046409 Popyeong village Angil maintenance work Deadline27 Mar 2026 12046410 [Veterinary Sidam] Pine wilt disease control project (3rd) (Imdong Maryeong District) Deadline24 Mar 2026 12046411 [Veterinary Sidam] Pine wilt disease control project (3rd) (Yeandochon Dongchon district) Deadline24 Mar 2026 12046412 Purchase of summer work uniforms and workwear spare parts at the Korea National Oil Corporation stockpile base site in 2026 Deadline23 Mar 2026 12046413 2026년 부여지사 물관리자동화시스템 유지관리 용역 Deadline23 Mar 2026 12046414 [Veterinary Sidam] Pine wilt disease prevention tree injection project (Pungsan Suri District 2) Deadline24 Mar 2026 12046417 Production of teaching materials and teaching materials using educational programs Deadline23 Mar 2026 12046419 Waste disposal service for sidewalk maintenance work in Namgwang Market area Deadline27 Mar 2026 12046420 [Veterinary Sidam] Pine wilt disease prevention tree injection project (Pungsan Suri District 1) Deadline24 Mar 2026 12046421 2026 Haman-gun Odor Management Area (Chilseo General Industrial Complex) Odor Survey Service Deadline27 Mar 2026
API Integration — seamlessly integrate global tender data into your systems
AI-Powered Tender Intelligence for smarter bidding decisions
Publish Your Tenders — reach a global network of suppliers
Source Tenders Faster — discover verified tenders from across the globe
Chat with us