The Trump administration asked a military base outside Chicago for support on immigration operations this week, offering a clue of what an expanded law enforcement crackdown might look like in the nation's third-largest city.

The Department of Homeland Security asked Naval Station Great Lakes for “limited support in the form of facilities, infrastructure, and other logistical needs to support DHS operations,” Matt Mogle, spokesperson for the base 35 miles (56 kilometers) north of Chicago, said Wednesday.

The request came weeks after the Republican administration deployed National Guard troops to Washington, D.C., to target crime, immigration and homelessness, and two months after it sent troops to Los Angeles.

Details about the administration's plans for Chicago remain scarce.

Mogle said no decisions have been made on the request, and that the base hasn't received an official request to support a National Guard deployment. The Chicago Sun-Times first reported on the request to the Navy base.

The Illinois National Guard had not received any requests regarding a Chicago mobilization as of Thursday, said Major Dutch Grove, a Guard spokesman.

Mayor Brandon Johnson and Illinois Gov. JB Pritzker have pushed back against a mobilization, saying crime has fallen in Chicago and that the city doesn't want or need the military's help. They are planning to sue.