It remained unclear how long the shutdown will last.
The US House of Representatives adjourned Friday without Congress passing a spending deal, assuring a partial government shutdown at midnight as President Donald Trump and lawmakers remain at odds over border wall funding.
Operations for several key agencies will cease in the early hours of Saturday, despite last-ditch talks that continued on Capitol Hill between White House officials and congressional leaders in both parties.
Trump is seeking $5 billion for construction of a wall on the US border with Mexico. Democrats are staunchly opposed, and the absence of an elusive deal means federal funds for dozens of agencies will lapse at midnight.
It remained unclear how long the shutdown will last. But the optics are bad, as hundreds of thousands of federal employees will be either furloughed or forced to work without pay in the run up to the Christmas holiday.
The House is due back in session at noon (1700 GMT) Saturday.
The Senate meanwhile remained open late Friday, but there were no signs yet of a breakthrough, and the chamber was quiet.
Senators told reporters that congressional leaders from both parties were negotiating behind the scenes with White House officials including Vice President Mike Pence, Trump's son-in-law Jared Kushner, and incoming chief of staff Mick Mulvaney.
One focus of discussion was the $1.6 billion in border security funding that was a part of pending Senate legislation, number two Senate Republican John Cornyn told AFP.
But conservatives in the House would likely balk at that figure.
"There's no agreement," congressman Mark Meadows, chairman of the House Freedom Caucus of ultra-conservatives, told reporters as he made his way from Senate meetings to the House.
"There's a whole lot of numbers being thrown around," but a maximum $1.6 billion for border security "is not acceptable."
Trump was scheduled to fly to Florida late Friday for his Christmas break, but the White House said the president postponed the trip and would remain in Washington in an effort to salvage a spending deal.