The speculation follows "border czar" Tom Homan’s promise to “flood the zone” – New York City – with U.S. Immigration and Customs Enforcement agents. The threat followed last weekend’s shooting of an off-duty Customs and Border Protection agent at Fort Washington Park in Upper Manhattan.

The case filed Thursday is the latest attempt by the Trump administration to sanction New York City over its "sanctuary" policies. Earlier this year, the administration began to claw back tens of millions of dollars that had already been allocated by Congress in migrant-crisis reimbursements.

The Justice Department says city officials are intentionally obstructing enforcement of federal immigration law.