United States senators on Sunday inched closer to a deal to end the government shutdown, with federal agencies remaining closed as the work week began, The New York Times reported.

A bipartisan group of senators worked through the day to shape a deal that would satisfy both the Democrats and Republicans. But at night, Majority Leader Senator Mitch McConnell of Kentucky announced that a vote had been postponed till noon on Monday.

Many federal employees will be “furloughed” – on unpaid leave – until the deadlock is broken, the BBC reported. Callers to the White House are being greeted with an answering machine message that say the phone line is closed because the Democrats are “holding government funding hostage”, ABC reported.

The Democrats want President Donald Trump to negotiate over immigration rules and permanently extend the “Dreamers” programme that granted temporary legal status to undocumented immigrants. In September 2017, Trump had ended the programme and allowed the Congress to replace it by March 2018.

The Republicans, however, said no negotiation is possible when federal government services are closed. The Republicans also want funding for border security, including a proposed border wall with Mexico, reforms to the immigration system and an increase in military spending.

The group of senators from both parties who are trying to reach a compromise are discussing a plan that would see the US government stay open through early February, while the Senate tackles the immigration issue in the next few weeks.