Immigration and Customs Enforcement agents will go to work in US airports as a funding dispute causes widespread travel chaos across the country.

Transportation Security Administration personnel are quitting in droves or just not showing up to work because of a partial US government shutdown that means they will miss a second full paycheque this coming Friday.

At airports in Houston, New York and Atlanta, more than a third of ‌TSA staff were calling in sick or otherwise absent, the US Department of Homeland Security said on Sunday (local time).

The shutdown has left tens of thousands working without pay while congressional Democrats and Republicans argue over the DHS budget.

DHS said on Saturday that more than 10 per cent of TSA officers called in sick on more than half of the past seven days, while more than 400 had quit since the partial shutdown began on February 14.

TSA has about 65,000 employees, including 50,000 airport security officers.

The staff shortage has led to long queues at American airports, as many travellers head off for spring holidays. To help fill the gaps, hundreds of ICE agents would deploy to airports from Monday, officials said.

The announcement came a day after US President Donald Trump posted to social media that ICE agents would be sent in. Their activities would include “the immediate arrest of all Illegal Immigrants ​who have come into our Country”, particularly Somalis, a group that Trump’s administration has accused, without evidence, of widespread fraud and corruption.

“I will move our brilliant and patriotic ICE Agents to the Airports where they will ​do Security like no one has ever seen before,” he wrote on Truth Social.

DHS said on Sunday it would not publicly share details about the ICE deployment, to preserve operational security. But sources said the plan called for initially sending ICE agents to 14 locations.

However, they won’t yet be deployed in areas behind airport security checkpoints because they lack the necessary clearance, the sources said.

Atlanta Mayor Andre Dickens said his office had been informed that ICE agents would be sent on Monday to Hartsfield-Jackson, the busiest US airport in passenger numbers.

Federal officials indicated that the ICE deployment would support TSA in crowd control ‌and managing security lines in domestic ‌terminals, and is “not intended to conduct ⁠immigration enforcement activities”, Dickens said.

So-called White House border czar Tom Homan said ICE agents wouldn’t be directly involved in security scanning.

“I don’t see an ICE agent looking at an X-ray machine, because we’re not trained in that,” he told CNN’s State of the Union.

“But there are certain parts of security that TSA is doing that we can move them off those jobs, and put them in the specialised jobs to help move those lines.”

Democrats have held up funding for DHS while demanding a change in rules governing its immigration operations, which have killed US citizens and sparked public outrage.

ICE has played a central role in the Trump administration’s ⁠immigration crackdown, drawing criticism from many Democrats, civil liberties advocates and immigration advocacy groups.

Senator ‌Richard Blumenthal, a ​Connecticut Democrat, criticised Trump’s proposal as “another reckless, lawless threat to misuse ICE agents”.

“He seems to have no concept of what the limits are on ICE, and I ​think America would ‌be absolutely appalled to see ICE agents roaming through airports, just as they’ve been breaking down doors at homes,” Blumenthal said in Washington.

Democratic Representative Hakeem Jeffries told CNN that using ICE agents would risk lives.

“The last thing that the American people need are for untrained ICE agents to be deployed at airports all across the country, potentially to brutalise or in some instances kill them,” he said.

“We’ve already seen how ICE conducts itself,” Jeffries said, referring to the fatal shootings of Alex Pretti and Renee Nicole Good by federal agents in Minneapolis during an immigration crackdown.

Homan said sending immigration ‌agents to bolster short-staffed TSA ​teams would speed up airport lines.

“When we deploy tomorrow, we’ll have a well thought-out plan to execute,” Homan ​told CNN.

“ICE will do the job far better than ever done before!” Trump wrote in a social media post.

-with AAP