Chicago Mayor Lori Lightfoot says the city’s police department will not participate in an U.S. Immigration and Customs Enforcement roundup of migrant families who have been ordered out the country.

ICE agents have been directed by President Donald Trump to conduct pre-dawn raids in major U.S. cities on Sunday, according to published reports.

President Trump said on Monday that U.S. authorities would begin next week removing millions of immigrants who are in the United States illegally.

“Next week ICE will begin the process of removing the millions of illegal aliens who have illicitly found their way into the United States. They will be removed as fast as they come in. Mexico, using their strong immigration laws, is doing a very good job of stopping people…” the president tweeted.

In a statement released Friday, Lightfoot says she has directed the Chicago Police Department to terminate ICE access to its databases related to federal immigration enforcement activities. She says Superintendent Eddie Johnson confirms the order has been carried out.

Lightfoot said she has spoken to ICE officials in Chicago and voiced her objection to any roundup of migrant families.

In her statement, Lightfoot said Chicago “will always be a welcoming city and a champion for the rights of our immigrant and refugee communities.”

There are an estimated 12 million immigrants who are in the United States illegally, mainly from Mexico and Central America, according to Reuters.