MIAMI, United States (AFP) — The mayor of Miami-Dade County in Florida on Thursday told jails to obey President Donald Trump’s order to enforce US immigration laws, in a bid to clean up its reputation as a “sanctuary” for illegal immigrants.

Mayor Carlos Gimenez took the action after Trump threatened to cut federal funding to cities and areas that act as “sanctuaries” for illegal immigrants.

The term “sanctuary” refers to about 300 American cities, counties or states — such as New York or California — that protect undocumented immigrants from deportation by refusing to assist or cooperate with federal immigration officials.

Gimenez told the county’s Department of Corrections it must “honour all immigration detainer requests received from the Department of Homeland Security,” the mayor’s spokesman, Michael Hernandez, told AFP.

The Republican mayor was seeking favour with the president, who on Wednesday announced federal funding would be cut to so-called “sanctuary” cities.

The mayors of sanctuary cities New York, Los Angeles and San Francisco have defied that order and vowed to protect the immigrants.

Such cities normally do not allow local police to inquire about the immigration status of people with whom they interact.

They also refuse to detain people brought to them by immigration authorities or to keep suspected undocumented immigrants in jail beyond their scheduled release date.

Until Thursday Miami-Dade County refused to detain illegal immigrants unless the federal government reimbursed the county for the expense.

Gimenez said in an interview with the Miami Herald that his decision was financial.

“I want to make sure we don’t put in jeopardy the millions of funds we get from the federal government for a US$52,000 issue,” said Gimenez, who voted for Democrat Hillary Clinton.

Keeping immigrants in local jails last year cost Miami-Dade County US$52,000.

“It doesn’t mean that we’re going to be arresting more people. It doesn’t mean that we’re going to be enforcing any immigration laws,” Gimenez said.

Trump fired off on his Twitter accounts in praise of Gimenez.

“Miami-Dade Mayor drops sanctuary policy. Right decision. Strong!” the president tweeted on his personal account @realDonaldTrump, then retweeted using his official White House handle.

According to the research group Migration Policy Institute, Florida has 650,000 undocumented immigrants. It ranks fourth in states with the largest populations of illegal immigrants, behind California, with more than three million; Texas, with 1.5 million; and New York with 870,000.

Broward County, north of Miami-Dade, also is considered a “sanctuary” and like its neighbour wants to clean up that reputation, its sheriff Scott Israel told the ABC television network.

Since taking office last Friday, Trump has signed executive orders that raised fears among many immigrants during his election campaign. He ordered the crackdown on “sanctuaries” and the building of a wall along the US-Mexican border on Wednesday.