The U.S. Senate and House of Representatives were expected to vote on a proposed budget deal on Thursday that would avert another government shutdown but that has angered fiscal conservatives who complain it would lead to a $1 trillion deficit.
The plan to keep the government operating and to increase spending over the next two years faced resistance from conservatives in the Republican Party, who favour less spending on domestic government programs.
At the same time, many liberal Democrats wanted to withhold their support as leverage to win concessions on immigration policy.
That meant the bill's passage was not assured in the House and would need some Democratic support.
House Speaker Paul Ryan, a Republican who has backed the agreement, said he believed the chamber will pass the budget deal.