Mayor Lori Lightfoot wrote an open letter to President Donald Trump for the Washington Post about why Chicago police would not aid ICE raids that had been slated to begin in the city this weekend.

“I ordered my city’s police department not to cooperate with Immigration and Customs Enforcement (ICE) on any activities within the city of Chicago and not to allow ICE agents access to our police databases,” Lightfoot wrote in the op-ed that was published Sunday evening.

“I took these steps in response to a set of policies from your administration that don’t make us safer or stronger as a nation,” Lightfoot wrote.

“There are approximately 180,000 undocumented people living in the city of Chicago, working, riding the public transportation system, sending their kids to public schools and attending City Colleges,” Lightfoot wrote.

The mayor said immigrants she meets express “fear, confusion and anxiety” about threats Trump has made to round up and deport certain illegal immigrants in nationwide sweeps by U.S. Immigration and Customs Enforcement. Such raids were set to begin in Chicago this weekend, but immigrant advocacy officials said Sunday night they could not confirm or verify reports that ICE activities occurred in Chicago.

“Fear of families being separated, confusion about the scope of their rights and anxiety that the next knock on the door, the next traffic stop could irreparably upset the lives they have built for themselves in our city,” Lightfoot wrote.

Lightfoot praised immigrants’ contributions toward local economy, business and infrastructure, and criticized Trump’s plan for raids as misguided. “The threats and realities of stepped-up enforcement have not had the deterrent effect you intended, because the people you are targeting are not actually the problem.”

The mayor urged the president to “rethink the harmful policies that your administration is promoting … ” and said her “wonderful, diverse and uniquely American city” would not be silent as raids commence.

“Any such efforts by ICE in our city will be met with fierce resistance from Chicagoans who have been organizing tirelessly in their communities, and with an unshakable resolve to stand with, and never against, our immigrant neighbors.”

Read the full op-ed here.