Hundreds of thousands of federal workers will be unable to report for work on Monday, as the US Senate struggles to end a government shutdown.
The shutdown began at midnight on Friday, when lawmakers failed to agree on an extension to federal funding.
Efforts to reach a compromise ahead of the working week failed late on Sunday.
A vote to end the shutdown was postponed until midday (17:00 GMT) on Monday, meaning many federal government offices will remain closed.
The Senate held a rare session throughout the weekend, in an attempt to reach an agreement ahead of the working week.
But there was little sign of compromise, as Democratic and Republican senators blamed each other.
Democrats want President Trump to negotiate over immigration as part of a budget deal, but Republicans say no agreement is possible while federal government services are closed.
Republicans want funding for border security – including a proposed border wall with Mexico – and immigration reforms, as well as increased military spending.
The session was adjourned at about 21:30 on Sunday (Monday 02:30 GMT). A vote, initially scheduled for early on Monday, was postponed until the afternoon.
The failure to agree on a deal means many federal employees will be “furloughed” – on unpaid leave – until the stalemate is resolved.
On Saturday, Mr Trump said the “nuclear option” of a simple majority vote was necessary to end the impasse.
This is because, under Senate rules, the bill needs 60 votes in the 100-member chamber to overcome blocking tactics by opponents.
The Republicans currently have 51 senators which is why they need some Democratic support to pass a budget.
The last government shutdown was in 2013, and lasted for 16 days.
It cost the government $2bn in lost productivity and led to “significant negative effects on the economy”, the OMB said at the time.