President Donald Trump said Saturday he will order federal immigration officers to take a role in airport security starting Monday unless Democrats agree on a bill to fund the Department of Homeland Security.

In a pair of social media posts, Trump first threatened and then said he had made plans to put officers from U.S. Immigration and Customs Enforcement in airports if the congressional standoff continues. He made the announcement as a partial shutdown contributes to long lines to pass through screening at some of the nation's largest airports.

The Republican president suggested ICE agents would bring the administration’s immigration crackdown into the nation’s airports, promising to arrest “all Illegal Immigrants."

“I look forward to moving ICE in on Monday, and have already told them to, “GET READY.” NO MORE WAITING, NO MORE GAMES!” Trump wrote while spending the weekend in Florida.

The move appears to be a pointed effort to expand the type of immigration enforcement that has become a sticking point in Congress. Democrats pledged to oppose funding for DHS unless changes were made in the wake of a crackdown in Minnesota that led to the fatal shootings of two protesters. Democrats are asking for better identification for federal law enforcement officers, a new code of conduct for those agencies and more use of judicial warrants, among other measures.

The Minnesota operation was tied in part to allegations of fraud involving Somali residents. On Saturday, Trump said ICE officers sent to airports would focus on arresting immigrants from Somalia who are in the United States illegally. Repeating his criticism on Somalis, he said they “totally destroyed” Minnesota.

“If the Democrats do not allow for Just and Proper Security at our Airports, and elsewhere throughout our Country, ICE will do the job far better than ever done before,” Trump said.

Trump’s posts did not offer additional detail on how ICE would take a role in airport security and what it meant for the Transportation Security Administration, which screens passengers and luggage for hazardous items.

The vast majority of TSA employees are considered essential and continue to work during the funding lapse, but they are doing so without pay. Call-out rates have started to increase at some airports, and DHS said at least 376 have quit since the partial shutdown began Feb. 14.

On Saturday, in a rare weekend session, the Senate rejected a motion by Democrats to take up legislation to reopen TSA and pay workers who are now going without paychecks. Republicans argue that they need to fund all parts of the DHS, not just certain ones. A bill to fund the Cabinet department failed to advance in the Senate on Friday.

There were signs of progress, though, with the restarting in recent days of stalled talks between Democrats and the White House. On Saturday, Republican and Democratic senators were set to meet for a third consecutive day with White House officials behind closed doors as Senate Democratic leader Chuck Schumer of New York spoke of “productive conversations.”

Senate Majority Leader John Thune, R-S.D., urged the bipartisan group to act quickly. He has said repeatedly that Democrats and the White House need to find compromise as lines at airports have grown.

“If that group that’s meeting can’t come up with a solution really quickly, things are going to get worse and worse,” Thune said Saturday.