Negotiators in Congress reached a tentative agreement on Monday night to stave off another government shutdown and pay for the construction of new barrier along the southern U.S. border.

Sen. Jon Tester, a member of the Senate team of negotiators, said the work isn't over yet. President Donald Trump has threatened to close the government again this Friday or do an end-run around Congress by declaring a national emergency if a suitable deal isn't reached.

“Our bipartisan committee did its job and crafted a compromise that will help secure our borders and keep the government open,” Tester said. “Montanans deserve that kind of certainty from their lawmakers, and I look forward to working with my colleagues over the coming days to shepherd this bill through the legislative process.”

The deal announced Monday includes $1.4 billion for new barrier. That's less than the $5.7 billion Trump demanded before closing the government last month.

More details of the agreement are expected today.

Sen. Steve Daines, who is not a member of the negotiating team, toured the border over the weekend.

“It is more clear than ever we must #SecureOurBorder as we witnessed firsthand the impacts of a porous border,” Daines tweeted Monday before the deal was announced later in the evening.

The group of Senate negotiators includes Democratic Sens. Tester, Patrick Leahy of Vermont and Dick Durbin of Illinois, as well as Republican Sens. Richard Shelby of Alabama, John Hoeven of North Dakota, Shelley Moore Capito of West Virginia, and Roy Blunt of Missouri.

This story will be updated as more information comes available.