Don Terry, the Chicago police spokesman, said officers would not “intervene or interfere with any other government agencies performing their duties”.
But he added that it “does not document immigration status” and “will not share information with federal immigration authorities”.
The incoming Trump administration wants to send a signal that it is coming down hard on undocumented migrants and to punish the sanctuary cities. It will first target those with a criminal record.
The planned raids were first reported by the Wall Street Journal. A source told the newspaper that there would be raids all across the United States, and not just in Chicago.
“We’re going to be doing operations all across the country,” the source said. “You’re going to see arrests in New York. You’re going to see arrests in Miami.”
At an event in Chicago, Tom Homan, Trump’s border tsar, said: “If the Chicago mayor doesn’t want to help, he can step aside. But if he impedes us, if he knowingly harbors or conceals an illegal alien, I will prosecute him.”
Mr Homan has said the public should expect “shock and awe” in the early days of the new presidency after Mr Trump vowed to deport millions of illegal immigrants.
The border tsar has promised that the administration will even deport undocumented parents of US-born children, who qualify as citizens.
Mr Homan said: “New York City, Chicago, San Francisco, Los Angeles, the major cities in this country are still sanctuary cities.
“If they’re not going to help us, then we’ll just double the manpower in those cities.”
