A shutdown for the Department of Homeland Security appeared certain Thursday as negotiations between the White House and Democrats in Congress stalled and lawmakers prepared to leave Washington for a 10-day break. The impasse centered on Democrats’ demands for new restrictions tied to U.S. Immigration and Customs Enforcement and other federal law enforcement agencies, while the White House circulated a proposal that Democrats said did not meet their requirements.

Democrats said the White House and lawmakers were trading offers in recent days as they pushed for curbs on President Donald Trump’s broad campaign of immigration enforcement. Among their demands were better identification for ICE and other federal law enforcement officers, a new code of conduct for those agencies, and increased use of judicial warrants. They also sought changes aimed at reducing incidents they linked to last month’s fatal shootings of two protesters.

The White House sent its latest proposal late Wednesday, but Trump told reporters Thursday that some of the Democratic demands would be “very, very hard to approve.” Senate Democratic leader Chuck Schumer of New York said the White House offer, which was not made public, did not contain sufficient curbs on ICE after the shootings of two protesters last month, and he characterized the proposal as “not serious.” Schumer added that Americans want accountability and “an end to the chaos,” and he said the White House and congressional Republicans must “listen and deliver.”

With the shutdown fight looming, lawmakers in both chambers were on notice to return to Washington if a deal emerged that would end the expected shutdown. Senate Appropriations Committee chair Patty Murray told reporters that Democrats would send the White House a counterproposal over the weekend, setting up a final push after negotiators were scheduled to leave.

Senate Majority Leader John Thune said after the vote that a shutdown appeared likely and that “the people who are not going to be getting paychecks” would pay the price. He argued the immediate impact would likely be minimal, saying the DHS shutdown would not likely block immigration enforcement operations at first, in part because a tax and spending cut bill passed last year provided ICE about $75 billion to expand detention capacity and bolster enforcement operations.

Thune and other lawmakers cautioned that the broader DHS portfolio could face larger strains over time. Gregg Phillips, an associate administrator at FEMA, told a hearing this week that FEMA’s disaster relief fund has sufficient balances to continue emergency response during a shutdown, but that it would become “seriously strained” if a catastrophic disaster struck. Phillips said that while the agency would still respond to threats such as flooding and winter storms, long-term planning and coordination with state and local partners would be “irrevocably impacted.”

In the negotiations, Trump defended officer masking after noting a recent court ruling rejected a ban on masks for federal law enforcement officers, and he told reporters, “We have to protect our law enforcement.” Democrats’ demands for restrictions on ICE and other federal officers followed the shootings that Democrats tied to heightened tensions in immigration enforcement, including the fatal shooting of ICU nurse Alex Pretti on Jan. 24 by a Border Patrol officer in Minneapolis and the fatal shooting of Renee Good by ICE agents on Jan. 7.

Democrats and Republicans also clashed over how officers should handle identification and how federal enforcement should be conducted in the field. Schumer and House Democratic leader Hakeem Jeffries said immigration officers should remove masks to show identification and should better coordinate with local authorities, and they demanded a stricter use-of-force policy, legal safeguards at detention centers, and a prohibition on tracking protesters with body-worn cameras. They also said Congress should end indiscriminate arrests and require verification that a person is not a U.S. citizen before detainment.

Thune suggested there could be areas of compromise, including on masks, saying there could be contingencies “that these folks aren’t being doxed,” and adding, “I think they could find a landing place.” Republicans, however, largely opposed items on Democrats’ list, including a prohibition on masks. Sen. Eric Schmitt said Republicans who had pushed for stronger immigration enforcement would benefit politically from the Democrats’ demands, saying, “So if they want to have that debate, we’ll have that debate all they want.”

A key dispute also remained over judicial warrants. Thune said warrants would be “very hard” for the White House or Republicans to resolve, and Schumer and Jeffries said DHS officers should not be able to enter private property without a judicial warrant. They also said warrant procedures and standards should be improved and argued for ending “roving patrols” by agents targeting people in streets and homes.

Most immigration arrests are carried out under administrative warrants issued by immigration authorities that authorize arrest of a specific person, but do not allow officers to forcibly enter private homes or other nonpublic spaces without consent—authority they said traditionally requires warrants signed by judges. But Democrats pointed to an internal ICE memo obtained by The Associated Press last month that they said authorizes ICE officers to use force to enter a residence based solely on a narrower administrative warrant to arrest someone with a final order of removal, which advocates said conflicts with Fourth Amendment protections.

Even as the sides appeared to trade “concessions,” Thune said they were “a long ways toward a solution.” Schumer said it was not enough that the administration announced an end to the immigration crackdown in Minnesota that he tied to thousands of arrests and the fatal shootings of two protesters, and he said Democrats needed legislation to “rein in ICE and end the violence,” warning that the administration’s actions could be reversed. Partisan tensions played out on the Senate floor after the vote, including Alabama Sen. Katie Britt trying to pass a two-week extension of Homeland Security funding as Democrats objected, and Connecticut Sen. Chris Murphy responding that Democrats want to fund DHS but only a department that is “obeying the law.”