The Trump administration is expected to begin a large-scale crackdown on illegal immigration in the coming days in Chicago, a push that could bring hundreds of additional federal agents to the city and ignite tensions in Latino communities.

President Trump has been mentioning the effort for weeks as part of his broadening immigration enforcement across the country, which aims to arrest people in cities including Chicago that typically don’t coordinate with U.S. Immigration and Customs Enforcement.

Recently, Mr. Trump has described Chicago as a “mess,” the latest volley at a city that he has long criticized for its Democratic leadership and crime rate. He has already sent federal agents and troops to Los Angeles and Washington, and has said the moves are necessary to fight street crime and enforce immigration laws.

An internal document obtained by The New York Times indicated that Department of Homeland Security officials would arrive at the Naval Station Great Lakes this week and that there would be 30 days of operations in the Chicago area.

In Chicago, at least 150,000 people in the city of 2.7 million are undocumented, estimates show, making up about 8 percent of households.

Both political leaders and residents say they are uncertain what exactly is about to take place.

Hundreds of Chicago residents have vowed to gather in protest downtown at the first sign of I.C.E. raids, and metal barricades were placed around the federal courthouse on Thursday night in the heart of the Loop.