Donald Trump and his border czar, Tom Homan, have confirmed that the president’s administration is sending Immigration and Customs Enforcement (ICE) agents to US airports beginning Monday to assist with security amid extremely long lines – and to help airport security agents who have been working without pay since 14 February because of a partial government shutdown.

Homan will lead the effort, Trump said on Sunday.

In a post on Truth Social, Trump said “ICE will be going to airports to help our wonderful [Transportation Security Administration] Agents who have stayed on the job despite” the shutdown resulting from a US Senate deadlock over stricter regulations on federal immigration enforcement.

Homan, meanwhile, appeared on CNN’s State of the Union on Sunday and said “we will be at the airports tomorrow”. It remained unclear what responsibilities ICE officers will have, and Homan said on Sunday details were still being finalized.

“There’s TSA agents covering exits. People that enter through the exits. Certainly a highly trained ICE law enforcement officer can cover an exit, make sure people don’t go through those exits, enter an airport through the exits,” he said on CNN.

“Stuff like that relieves that TSA officer to go to screening and to reduce those lines. I don’t see an ICE agent looking at an X-ray machine because they’re not trained in that. There’s certain parts of security that TSA’s doing that we can move them off those jobs and put them in the specialized jobs and help them move those lines.”

More than 400 TSA agents have left their jobs since the partial government shutdown began, according to NBC News, and others are calling out sick. There have been crippling, hours-long waits at security checkpoints run by TSA across the US.

Images showed lines out to the parking lot at New Orleans’s airport on Sunday and at New York’s LaGuardia airport earlier in the weekend.

Senate Democrats have blocked funding for the Department of Homeland Security (DHS), which oversees TSA, seeking reforms after immigration agents killed US citizens Renee Good and Alex Pretti in Minneapolis in separate cases in January.

Pressed by CNN’s Dana Bash on how well thought out the plan could be if it was still being finalized on Sunday, Homan said: “How much of a plan does it mean [sic] to guard an exit to make sure no one comes through an exit?”

Trump said on Saturday ICE agents at airports would “do security like no one has ever seen before”.

The Trump administration has deployed ICE agents for immigration crackdowns across the country, a move that – in addition to the killings of US citizens – has led to civil rights violations.

The US House’s Democratic minority leader, Hakeem Jeffries of New York, came out strongly against ICE agents at airports in his own appearance on CNN.

“The last thing that the American people need are for untrained ICE agents to be deployed at airports all across the country, potentially to brutalize or in some instances kill them,” Jeffries said. “We have already seen how ICE conducts itself.”