US President Donald Trump's administration has directed prosecutors to investigate officials who resist immigration enforcement efforts, intensifying a sweeping crackdown that Trump launched the day he took office.

In a memo seen by Reuters, Trump's acting deputy attorney general, Emil Bove, told Justice Department staff that state and local authorities must cooperate with the immigration crackdown and federal prosecutors "shall investigate incidents involving any such misconduct for potential prosecution."

The Justice Department could also challenge laws that complicate the effort, Bove wrote.

The policy was issued as the new Republican administration prepared to step up policing of illegal immigration in cities with significant migrant populations, setting up potential confrontations with officials in cities such as New York and Chicago that limit cooperation with such efforts.

The new memo underscored how Trump's Justice Department may try to back his immigration agenda by expanding threats of criminal charges beyond immigrants or those who employ them to city and state officials. It is the latest in a series of executive actions Trump has taken to curb illegal immigration, his top priority.

During Trump's first 2017-2021 term in office, many Democratic officials refused to cooperate with his enforcement efforts, and some vowed to defy him again.

"We know that we don't have to participate in immigration enforcement activities," Democratic California Attorney General Rob Bonta said on CNN.

But resistance in the party is not monolithic this time. In the U.S. House of Representatives on Wednesday 46 Democrats - one-fifth of their number - joined 217 Republicans to pass legislation that would require immigrants who are in the country illegally to be held for deportation if they are accused of theft.

The bill has already passed the Senate with Democratic support and now heads to Trump's desk to be signed into law.

"The American people want us to do something about the border and I think we’d be hard-pressed to not say that we have to deport criminals," Representative Tom Suozzi, a moderate Democrat who voted for the bill, told Reuters.

TROOPS TO BORDER

Trump has issued a broad ban on asylum and taken steps to restrict citizenship for children born on American soil. A U.S. official said on Wednesday the military would dispatch 1,000 additional active-duty troops to the Mexico-U.S. border on Trump's orders.

The administration has rescinded guidance from his Democratic predecessor Joe Biden that had limited immigration arrests near schools, churches and other sensitive places. Trump has also expanded immigration officers' power to deport migrants who cannot prove they have been in the U.S. for longer than two years.

His move to expand fast-track deportations faced a legal challenge on Wednesday, with immigration advocacy group Make the Road New York filing a lawsuit arguing the policy known as expedited removal violated the constitutional right to due process, immigration law and administrative law.

U.S. civil rights groups meanwhile warned that an executive order signed by Trump on Monday - setting a 60-day window for officials to identify countries whose vetting and screening processes are "so deficient as to warrant a partial or full suspension on the admission of nationals from those countries" - laid the groundwork for reinstatement of a ban on travelers from predominantly Muslim or Arab countries.

Americans are sharply divided on Trump's plans for mass deportations. A new Reuters/Ipsos survey showed 39% agreed that "illegal immigrants should be arrested and put in detention camps while awaiting deportation hearings," while 42% disagreed and the rest were unsure.

Some 46% of respondents said they approved of how Trump was handling immigration policy, while 39% disapproved. Most respondents who backed mass arrests identified as Republicans, while most who did not were Democrats.

The poll, which surveyed adults nationwide on Jan. 20-21, found 58% of respondents agreed that the U.S. should "dramatically reduce the number of migrants allowed to claim asylum at the border," while 22% disagreed.