The Trump administration is deploying highly trained officers to boost arrests of unauthorised immigrants in cities including Los Angeles, Chicago and New York, in the latest move against localities that adopt "sanctuary" policies to protect them from deportation.
Members of the US Customs and Border Protection's (CBP) Border Patrol Tactical Unit will be among the officers deployed to cities to assist Immigration and Customs Enforcement (ICE).
They will also be sent to San Francisco, Atlanta, Houston, Boston, New Orleans, Detroit and Newark, New Jersey, CBP spokesman Lawrence Payne said in a statement.
The Tactical Unit's members undergo a "gruelling" training program designed to "mirror aspects" of US Special Operation Forces courses, according to details about the program published on the CBP website. The unit was launched in 1984 in response to rioting at immigration detention facilities.
Scores of Democrat-controlled cities and counties have adopted policies to limit cooperation with federal immigration enforcement, making them a target for Republican President Donald Trump, who has made immigration a centrepiece of his re-election campaign.
The move to boost ICE support in the targeted cities, first reported by the New York Times, marks the latest escalation in the administration's fight against these localities and comes just days after the Department of Justice filed lawsuits against the state of New Jersey and King County, Washington, where Seattle is located.
The Department of Homeland Security said last week it would bar New Yorkers from obtaining new and renewal Global Entry passes - which allow pre-approved travellers to bypass immigration queues when re-entering the US - and from participating in three programs that permit faster travel between the United States, Canada and Mexico, which could affect hundreds of thousands of travellers.
"ICE is utilising CBP to supplement enforcement activity in response to the resource challenges stemming from sanctuary city policies," ICE acting Director Matthew T Albence said.
"As we have noted for years, in jurisdictions where we are not allowed to assume custody of aliens from jails, our officers are forced to make at-large arrests of criminal aliens who have been released into communities."
The deployment will run from February through May, the New York Times reported, citing a CBP email.
The move drew criticism from some, including Ayanna Pressley, a Democratic congresswoman from Massachusetts whose district includes Boston.
"Let us be clear, this move has nothing to do with public safety, but rather serves only to further the Trump administration's agenda to intimidate and retaliate against cities that uphold the dignity and humanity of our immigrant neighbours," she said in an emailed statement.
"We will not stand for this."