The White House says it is preparing for a US government shutdown as Congress hit a stumbling block in its efforts to pass a stopgap spending bill before midnight.
With just hours to go before current federal funding expires, the effort stalled in the Senate when one lawmaker blocked a quick vote on the compromise bill, which includes a major budget deal that lifts federal spending limits.
The White House's Office of Management and Budget "is currently preparing for a lapse in appropriations," an OMB official said on condition of anonymity, calling on lawmakers to get the measure to President Donald Trump's desk "without delay."
With each passing hour, that result was looking less and less likely.
The bill, which extends government funding for six weeks and raises the federal debt ceiling, would break the cycle of government funding crises in time for what is set to be a bruising campaign for November's mid-term elections.
Despite simmering rebellion among Republicans and Democrats over a bipartisan budget agreement struck on Wednesday to end the logjam, the Senate had been aiming to vote on the deal later Thursday before sending it to the House.