Washington DC - US authorities will carry out mass arrests of undocumented immigrants across the country on Tuesday, Donald Trump's incoming "border czar" said.

The move would be among the first by Trump, who returns to the White House on Monday, to uphold a campaign pledge to deport millions of people from the US.

"There's going to be a big raid across the country. Chicago is just one of many places," said Homan, a former acting director of Immigration and Customs Enforcement (ICE) who oversaw a policy that separated parents and children at the border under the first Trump administration.

"On Tuesday, ICE is finally going to go out and do their job. We're going to take the handcuffs off ICE and let them go arrest criminal aliens," he said in the interview.

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"What we're telling ICE, you're going to enforce the immigration law without apology. You're going to concentrate on the worst first, public safety threats first, but no one is off the table. If they're in the country illegally, they got a problem," Homan added.

There were multiple reports of a "large-scale immigration raid" in Chicago, expected to start on Tuesday, a day after Trump's inauguration, and involving 100 to 200 ICE officers.

Don Terry, a Chicago police spokesman, told the New York Times that the department would not "intervene or interfere with any other government agencies performing their duties."

But he said the department "does not document immigration status" and "will not share information with federal immigration authorities."

Midwestern Chicago is one of several Democrat-led US cities that have declared themselves "sanctuaries" for migrants – meaning they will not be arrested solely for not having legal immigrant status.