The US government has shut down after politicians failed to agree a new budget, leaving hundreds of thousands of federal workers on unpaid leave.
In a dramatic night in Washington, Republican leaders fell short of the 60 votes needed in the Senate to pass a spending bill to fund the government until 16 February.
Without some type of funding bill, the US government technically ran out of money at midnight on Friday (5am Saturday UK time).
That forced the government shutdown, with scores of federal agencies across America unable to continue operating.
Republicans argue that the Democrats are holding the government hostage over demands to protect 700,000 "dreamer" immigrants brought to the country as children and now living in the US illegally.
As the midnight deadline passed, the White House said it will not negotiate with the Democrats on immigration until the end of the shutdown.
White House Press Secretary Sarah Huckabee Sanders said: "We will not negotiate the status of unlawful immigrants while Democrats hold our lawful citizens hostage over their reckless demands.
"When Democrats start paying our armed forces and first responders we will reopen negotiations on immigration reform."
The American Federation of Government Employees estimates about 850,000 workers, out of a total 3.5 million, could be told to stay home without pay until Congress reaches an agreement.
Food inspections, federal law enforcement, airport security checks, and other vital services will continue, as will social security, other federal benefit programmes and military operations.
But most federal workers will not be paid.
The last US shutdown lasted for 16 days in October 2013, with around 800,000 workers granted leave.
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Shortly before the vote, President Donald Trump tweeted that it was "not looking good for our great Military or Safety & Security on the very dangerous Southern Border".
As the shutdown loomed, Mr Trump cancelled his planned weekend trip to Florida where he was due to celebrate the one-year anniversary of his inauguration at his Mar-a-Lago resort.