WASHINGTON—Lawmakers were to resume negotiations over border security Monday in an effort to avoid another government shutdown this weekend, with talks set to focus on limits on the number of detention beds and funding levels for barriers.
The top four lawmakers on the House and Senate appropriations committees were convening Monday afternoon in a bid to resuscitate stalled talks, an aide said.
For months, the public dispute over border funding has largely focused on border barriers. But over the weekend, Republicans and Democrats hit an impasse over how many detention beds would be provided for people detained by Immigration and Customs Enforcement officials.
Democrats have long been seeking to limit the number of beds as a way to force the Trump administration to prioritize the detention of immigrants with criminal records above those who overstayed their visas, for example.
In the negotiations, Democrats have been working to secure some constraints on ICE as a concession from Republicans, in exchange for meeting GOP demands to build more physical barriers along the border. Republicans have balked at the limits on ICE beds, saying they don’t want to restrain their capacity to detain criminals.
The government’s funding expires at 12:01 a.m. on Saturday, just weeks after the end of a 35-day partial shutdown. Lawmakers had hoped to have reached a deal by Monday, and the weekend’s snag has set them back. Still, a looming deadline has often helped pressure Congress into cutting a deal that seemed elusive until the last minute.
President Trump remains a wild card in the negotiations, and the latest delays in reaching an agreement heightened prospects that he would declare a national emergency and seek to divert funds from elsewhere to go toward miles of a wall along the Mexican border. Such a move would meet swift legal challenges, and GOP lawmakers have raised concerns over siphoning military-construction or disaster-aid funds to build the wall.
Mr. Trump has been seeking $5.7 billion to go toward a border wall. The amount under negotiation is a range of $1.3 billion to $2 billion, which would include funding for barriers and other measures and could mark an increase from the last fiscal year.
Democrats, while balking at a wall, have signaled willingness to fund some physical barriers, such as fencing and levee walls, along the border. But they are also trying to force the administration to prioritize detaining criminals for deportation through changes that Republicans resisted over the weekend.
Democrats had proposed establishing a new limit on detention beds used by ICE officials when apprehending people for violations within the U.S., known as interior enforcement. Those beds would be capped at 16,500, within the existing overall cap of 40,520 beds funded in the fiscal year 2018 spending bill.
Democrats hope that such a limit would provide an incentive for officials to detain immigrants with a criminal record, rather than people who had overstayed their visas, for example.
“A cap on ICE detention beds will force the Trump administration to prioritize deportation for criminals and people who pose real security threats, not law-abiding immigrants who are contributing to our country,” said Rep. Lucille Roybal-Allard (D., Calif.), who leads the House Appropriations Homeland Security panel.
Republicans objected, wanting to exclude violent criminals from that cap. Without an agreement on ICE beds, talks on funding levels and physical barriers stalled.
“The Democrats do not want us to detain, or send back, criminal aliens! This is a brand new demand. Crazy!” Mr. Trump tweeted on Monday morning.
But the dispute over ICE beds has been raging under the radar for months. Liberal Democrats have been urging their leaders for weeks to not provide any additional funding to the Homeland Security Department or ICE in the negotiations.
Within the group of 17 lawmakers trying to cut a deal, Democrats had initially proposed lowering the overall cap to 35,520 beds, which Republicans rejected. The White House has urged Congress to increase funding for 52,000 beds.
Mick Mulvaney, Mr. Trump’s interim chief of staff, on Sunday said the possibility of another lapse in government operations couldn’t be ruled out. The five-week shutdown that began in December ended with a short-term spending bill that runs out Friday.
Mr. Mulvaney said Mr. Trump remained committed to getting a wall built “with or without Congress.”
Lawmakers also hope to wrap up details of a broader spending agreement to fund nine of 15 federal agencies through the rest of the fiscal year, which ends Sept. 30.
If Congress doesn’t reach an agreement by the end of the day on Friday, those agencies likely would shut down again, triggering a new round of unpaid work and furloughs across the government.
The stall in the talks also meant negotiators hadn’t reached any agreement on funding for the barrier along the Southern border. “We hit a snag here that prevented us from even getting to that,” the senior GOP aide said.
On Sunday, Sen. Jon Tester (D., Mont.) said on Fox News that he wasn’t certain negotiators would reach a deal. “But this group of people and the folks from the House, I think we’re going to end up with something that deals with detention beds, with barriers, with technology, with the challenges we have in the Southern border in a common-sense way.”
—Kate Davidson contributed to this article.