Donald Trump is "strongly" considering plans to send immigrants detained at the US-Mexico border to so-called "sanctuary cities".
The president confirmed reports in a tweet in which he criticised Democrats for for being unwilling to change "very dangerous" immigrations lawed.
"Sanctuary cities" are places with policies designed to limit co-operation with federal immigration actions.
Confirming the action, Trump wrote on Twitter : "Due to the fact that Democrats are unwilling to change our very dangerous immigration laws, we are indeed, as reported, giving strong considerations to placing Illegal Immigrants in sanctuary cities only."
He added: "The Radical Left always seems to have an Open Borders, Open Arms policy – so this should make them very happy."
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But mayors from across the country were quick to respond to the president's latest portrayal of immigrants and sanctuary cities as threats.
In New York City, where nearly 40 percent of the population are immigrants, Mayor Bill de Blasio said Trump's immigration policy was rooted in cruelty.
"He uses people like pawns," de Blasio said in a statement.
"New York City will always be the ultimate city of immigrants - the President's empty threats won't change that."
In Philadelphia, known as the city of brotherly love, Mayor Jim Kenney said it would be prepared to "welcome immigrants just as we have embraced our immigrant communities for decades."
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He said the White House was demonstrating "the utter contempt that the Trump Administration has for basic human dignity."
Responding to the president's tweet, the mayor of Los Angeles, Eric Garcetti, said: "These are people, not pawns, Mr. President."
Trump's latest move on immigration comes days after U.S. officials said they arrested or denied entry to over 103,000 people along the border with Mexico.
More than twice as many as the same period last year.
