Since February, Nassau County has detained over 1,400 illegal migrants for Immigration and Customs Enforcement (ICE) as local law enforcement prepares to assist with the Trump administration’s large-scale deportation initiative.

The detainees have been housed at East Meadow jail through a collaboration with federal authorities, announced by Nassau County Executive Bruce Blakeman earlier this year.

The collaboration set aside 50 cells in the lock-up to help with the Trump administration’s immigration crackdown.

“If they are committing crimes in the metropolitan area — they are a threat to Nassau County,” Blakeman told The Post about housing ICE’s detainees.

Per the agreement, migrants can be confined at East Meadow jail for a maximum of 72 hours before ICE either deports them or transfers them to a long-term detention facility, with the federal government reimbursing the county for the detention expenses.

Nassau County cops have also already handed over at least 15 migrants to ICE since January after discovering they were undocumented during unrelated arrests.

The arrests involved charges ranging from grand larceny to endangering the welfare of a child, according to Nassau Detective Lt. Scott Skrynecki.

Meanwhile, Nassau County officials announced last week that 10 local police officers selected to be deputized as ICE agents under the partnership have now completed their training — and are ready to begin assisting in deportations once they get the green light from the feds.

The expansion of Nassau County’s partnership with the feds comes after neighboring Suffolk County was slapped with a $60 million fine when a judge ruled the county violated state law and the Fourth Amendment by holding hundreds of migrants past their release dates at ICE’s request between 2016 and 2018.

However, Suffolk officials told The Post that many were held past their release dates because ICE failed to pick them up on time.

The suspects had been arrested on unrelated charges and were only identified as undocumented during routine booking, officials added.

In Nassau County, most of the migrants who have been held for ICE have been shipped out within the 72-hour window, officials said.

Still, immigration advocates and civil rights groups have raised red flags over the county’s entanglement with federal immigration enforcement — warning that Nassau could face similar legal trouble.

Nassau County is already embattled in court cases over the partnership.

The New York Civil Liberties Union, which sued the county last month in an effort to block the ICE partnership, argues the program could lead to racial profiling and unlawful detentions if local cops begin acting as immigration agents on Long Island streets.

Blakeman has brushed off those concerns.

“We’re confident that all measures taken to protect communities in Nassau County are legal and properly authorized,” he said last month.

In preparation for the partnership with ICE to expand, Nassau recently tweaked its controversial mask ban. The new executive order signed by Blakeman will let cops and federal agents wear face coverings during undercover operations.