The US Congress is scrambling to avert a partial government shutdown, hours after more than three dozen Republicans rejected a demand by President-elect Donald Trump to use the measure to lift the nation's debt ceiling.
Republican House of Representatives Speaker Mike Johnson was trying to plot a course that could pass both his chamber, with narrow Republican control, and the Democratic-majority Senate, as a midnight Friday (local time) funding deadline loomed.
"We have a plan," Johnson told reporters at the Capitol on Friday.
"We're expecting votes this morning."
Conservative Republicans on Thursday rejected Trump's demand to lift the debt limit, which could add trillions more to the government's $US36 ($A58) trillion in debt.
Trump, who takes office in one month, overnight ratcheted up his rhetoric, calling for a five-year suspension of the US debt ceiling even after members of his party's right flank baulked at an earlier two-year extension.
"Congress must get rid of, or extend out to, perhaps, 2029, the ridiculous debt ceiling. Without this, we should never make a deal," Trump wrote in a post on his social media platform.
An earlier bipartisan deal was scuttled after Trump and his ally Elon Musk, the world's richest person, came out against it on Wednesday.
A hastily revised alternative backed by Trump then failed by a vote of 174-235 Thursday night.
That revised measure generally would keep the roughly $US6.2 ($A9.9) trillion federal budget running at its current level through March and provided $US100 billion ($A160 billion) in disaster relief.
But it dropped other measures included to appease Democrats, who still control the US Senate and the White House for four more weeks.
The White House has said President Joe Biden opposed the reworked bill.
Previous fights over the debt ceiling have spooked financial markets, as a US government default would send credit shocks around the world.
The limit has been suspended under an agreement that technically expires on January 1, though lawmakers likely would not have had to tackle the issue before the spring.