The US Congress has failed to agree a budget by 1 October and a federal government shutdown has begun, sending more than 700,000 federal workers home and closing down national parks, museums, federal buildings and services.
Which key departments and agencies are affected?
Department of Defense
The nation's 1.4 million active-duty uniformed military personnel will stay on duty. About half of the defence department's 800,000 civilian employees will have to stop work, but there is a blanket exception for activities that "provide for the national security".
But where employees are needed to work, they may have to do so without pay: "Military and other civilians directed to work would be paid retroactively once the lapse of appropriation ends," according to Defence Department Comptroller Robert Hale.
President Barack Obama later told civilian employees that they deserved "better than the dysfunction we're seeing in Congress".
Department of Energy
Employees: 13,814 Due to work: 1,113 Staying at home: 12,701 Most Department of Energy facilities will close, with only 1,113 out of 13,814 staff required to work. Hydroelectric dams will be maintained.
Exemptions include staff overseeing the safety of the nation's nuclear arsenal and operating dams and power lines across the country.
The National Nuclear Security Administration, which oversees the nation's nuclear weapons and naval reactor programmes, will have 343 employees on duty to "perform functions related to the safety of human life and the protection of property".
More than 400 employees will stay on to work at the Southwestern Power Administration and the Western Area Power Administration, which are in charge of overseeing hydroelectric power and power lines in the south and western US.
Some staff in other areas will remain at work to oversee "the protection of human life and property."
Department of Commerce
Employees: 46,420 Due to work: 6,186 Staying at home: 40,234. Ocean and the San Diego skyline Weather and shipping reports will still be provided.
Most of the department's staff will remain at home. However, staff at the National Oceanic and Atmospheric Administration will continue to report for duty to ensure weather, shipping and other reports are still provided for public safety.
Some of the workers at the Bureau of Industry and Security, which reviews exports, will also remain on duty.
Department of Transportation
Employees: 55,468 Due to work: 36,987 Staying at home: 18,481 Airport Most air traffic control roles will not shut down.
Transport roles run by the department, ranging from air traffic control to airport and hazardous materials inspections, will continue and 36,987 out of 55,468 personnel will remain at work.
Staff involved in overseeing commercial space launches will also continue operations - as at least one of a succession of launches will occur between the end of September and the first week in October in support of the International Space Station, according to the department.
Suspended activities will include facility security inspections, routine personnel security background investigations and the employee drug testing program.
Smithsonian Institution
Employees: 4,202 Due to work: 688 Staying at home: 3,514 Tian Tian Animals at the National Zoo will still be fed.
The National Zoo and 19 museums and galleries, including the Natural History Museum, the Portrait Gallery and the Air and Space Museum, would close.
Of the 4,202 employees, 688 will be retained to "protect life and property" - security guards, maintenance staff and people to care for and feed the animals at the National Zoo.
The Smithsonian Institution says: "During a shutdown, the Institution cannot legally accept voluntary services from federal employees to continue their regular duties."
National Parks
Employees: 24,645 Due to work: 3,266 Staying at home: 21,379
National parks - from Yosemite to Alcatraz and the Statue of Liberty - will be shut down with 3,266 essential staff out of 24,645 remaining on duty. These will include some fire management, law enforcement and emergency responders.
Day-use visitors will be instructed to leave the park immediately and visitors using overnight facilities will be asked to make alternative arrangements and leave.
Where possible, park roads will be closed and access denied.
Department of Homeland Security
Employees: 231,117 Due to work: 199,822 Staying at home: 31,295 Coast Guard Coast Guard operations will continue.
About 86% of the Department of Homeland Security's 240,000 employees are expected to be exempt from the shutdown, including uniformed agents and officers at the country's borders and ports of entry.
Most members of the Coast Guard, Transportation Security Administration, Secret Service and other law enforcement agencies are exempt.
US Citizenship and Immigration Services employees will continue to process green card applications.
Department of Justice
Employees: 114,486 Due to work: 96,744 Staying at home: 17,742 Of 114,486 Department of Justice employees, an estimated 96,744 will be exempt from the shutdown.
All Federal Bureau of Investigation (FBI) agents and support personnel in the field will be exempt as their operations are focused on national security and investigations involving protection of life and property.
Drug Enforcement Administration agents working on active counternarcotics investigations, agents in the Bureau of Alcohol, Tobacco, Firearms and Explosives, and US attorneys will be exempt.
Staff at federal prisons will also be expected to work.
Department of Health and Human Services
Employees: 78,198 Due to work: 37,686 Staying at home: 40,512
The department will be sending home more than half its workers. The annual flu programme will not be supported.
The Centers for Disease Control and Prevention will continue "minimal support to protect the health and well-being of US citizens". However, fewer staff will mean reduced capacity to respond to outbreaks and the agency will be unable to support its annual flu program.
Department of Education
Employees: 4,225 Due to work: 212 Staying at home: 4,013 Students eating breakfast Funding for schools, due this month, will be paid.
About 212 of the department's 4,225 employees - both full and part-time - will be expected to work for the first week. An additional 30 staff may be called in if the shutdown lasts more than seven days.
Some $22bn of funding to schools, due on the 1 October, will still be distributed. Among other things, this pays to help educate poor and disabled children.
Environmental Protection Agency
Employees: 16,205 Due to work: 1,069 Staying at home: 15,136
Administrator Gina McCarthy said her department would effectively shut down with only a core group of individuals available in case of a "significant emergency".
US Postal Service
The self-funded US Postal Service will remain open and deliver as usual. The agency receives no tax dollars for day-to-day operations and relies on income from stamps and other postal fees to keep running.
www.bbc.co.uk/news/world-us-canada-24302508
[про это на русском от Евроньюс...]В экономике любой страны рабочие места государственного сектора - это залог экономической безопасности. В Соединенных Штатах работы и зарплаты лишились 800 тысяч госслужащих. Конгресс не смог принять бюджет на новый финансовый год. Республиканцы и демократы упорно стояли на своем и ни на какие уступки не шли. США пошли по наихудшему сценарию, но что будет дальше?
Евроньюс: - С нами на связи наш вашингтонский корреспондент Штефан Гробе со своим взглядом на происходящее. Какая обстановка в американской столице, Штефан? Что происходит в стране, где стольким работникам было сегодня сказано “возвращаться домой” Какие последствия могут быть у этого политического противостояния?
Гробе: - Получилось так, что сотни тысяч государственных служащих оказались в отпуске на неопределенное время. Это означает, что они лишены зарплаты до тех пор, пока Конгресс не придет к согласию. Национальные парки и памятники, от Йосемити до Статуи Свободы сегодня закрыты. И если приостановка расходов продлится до конца октября, даже ветераны не получат свои пособия. Так что остановка финансирования немедленно повлияет на жизнь совершенно конкретных людей.
Евроньюс: - И что думают по этому поводу американцы? Какие будут следующие политические шаги?
Гробе: - Ну что же, должен отметить, что американцы смотрят на этот тупик в Вашингтоне с неприязнью. И конца ему не видно. Республиканский лагерь настаивает на том, чтобы любой ценой отложить вступление в силу Obamacare, чтобы позволить правительству продолжить работу. Демократы в Сенате и Обама называют это шантажом и не идут на переговоры. И это не единственная баталия вокруг бюджета этой осени. Потолок государственного долга должен быть поднят до середины октября, с тем, чтобы в ноябре, декабре можно было принять бюджет на 2014 год. Главный вопрос в том, сколько сможет продержаться каждый лагерь.
Евроньюс: - Сегодня первый день, когда начала действовать, введенная Обамой система медицинского страхования. Люди могут по интернету заключить соглашение о медицинской страховке…
Гробе: - Речь идет о записи онлайн, когда люди могут присоединиться к системе медицинского страхования, запущенной сегодня, и остановка работы правительства на это абсолютно никак не влияет. Эта система финансируется из средств, которые уже были выделены. Очевидно, что не удастся избежать кое-каких проблем, как всегда, когда начинается что-то широкомасштабное, но в конце концов все рассчитывают, что запуск Оbamacare пройдет гладко, и также спокойно будет работать в дальнейшем.
Евроньюс: - Это был наш вашингтонский корреспондент Штефан Гробе.