Lawmakers have just one day to try to prevent the first US government shutdown in 17 years, but a deal appeared remote on Monday as congressional leaders showed little intent to compromise.

With Congress going into crunch sessions ahead of an 11:59 pm (11.59 am Beijing time on Tuesday) deadline, a House Republican leader offered a glimmer of hope when he hinted that his party could offer a new plan that might pass muster in the Democratic-held Senate.

"I think the House will get back together in enough time, send another provision not to shut the government down, but to fund it, and it will have a few other options in there for the Senate to look at," No 3 House Republican Kevin McCarthy told Fox News on Sunday.

Congress must pass a stopgap funding measure before the new fiscal year begins on Tuesday or much of the US federal government will close down.

The procedure became dramatically more complicated when Republicans linked the budget legislation to an attempt to thwart President Barack Obama's healthcare law.

After the Senate passed a straightforward spending bill on Friday, the House countered following hours of debate on Saturday by attaching amendments seeking a one-year delay to so-called Obamacare, as well as repeal of a medical device tax which helps fund the law.

Democratic Senate Majority Leader Harry Reid, who refused to call the chamber into session over the weekend despite the rapidly approaching deadline, warned before the vote that such a measure would be dead on arrival.

The White House also sharply rebuked the move, and warned that the president would veto it even if the Senate did approve it.

On Monday "the Senate will do exactly what we said we would do and reject these measures," Reid spokesman Adam Jentleson said.

"At that point, Republicans will be faced with the same choice they have always faced: put the Senate's clean funding bill on the floor and let it pass with bipartisan votes, or force a government shutdown."

Republican McCarthy hinted that if the Senate rejected the measure as expected, the new House approach would still retain a provision "that I believe the Senate can accept, that will have fundamental changes in Obamacare".