CHICAGO (Reuters) - Chicago is starting an advertising campaign to reassure immigrants that they are welcome in the third-largest U.S. city, in a show of defiance to a crackdown by President Donald Trump on people who have entered the country illegally.

FILE PHOTO: Chicago Mayor Rahm Emanuel speaks with media after meeting with U.S. President-elect Donald Trump at Trump Tower in Manhattan, New York City, U.S. December 7, 2016. REUTERS/Andrew Kelly/File Photo

Mayor Rahm Emanuel said on Monday he was not worried about the “One Chicago” campaign upsetting the Trump administration.

Starting this week, signs will appear at more than 200 locations including digital billboards, trains and newspaper racks with photos of Chicago immigrants highlighting the diversity of their backgrounds. Radio and TV spots will start this week with similar stories. A new website, onechi.org, features links for free legal aid and “know your rights” training.The campaign’s slogan is “Three million residents, three million stories, one Chicago.”

The mayor’s office said the campaign was costing taxpayers nothing. The advertising was designed on a pro-bono basis by the ad agency Ogilvy Chicago and uses city-owned public-service advertising space.

“I’m not worried because we’re not only on firm legal ground but firm moral ground,” Emanuel said. “We’re all immigrants and we’re not going to let them divide us and say that person is not allowed here.”

Trump already has threatened to withhold federal funds from cities such as Chicago that offer sanctuary to illegal immigrants who commit no serious crimes. The Justice Department in April singled out Chicago and New York, saying they were “crumbling under the weight of illegal immigration and violent crime,” even though experts say illegal immigration had little to do with Chicago’s spike in murders.

Last month, a U.S. judge blocked a portion of Trump’s executive order that sought to withhold most federal funds from so-called sanctuary cities as part of the administration’s efforts to toughen immigration enforcement.

U.S. Attorney General Jeff Sessions issued a memo on Monday saying that only Department of Justice and Homeland Security grants would be at risk for cities that “willfully refuse” to comply with federal law.

Sanctuary cities generally offer safe harbor to illegal immigrants and often do not use municipal funds or resources to advance the enforcement of federal immigration laws.

Emanuel, whose grandparents came to the United States as immigrants from Moldova, said the campaign was meant to reassure those feeling frightened about deportation. Chicago officials estimates there are about 300,000 undocumented immigrants in the city.

“I see it with kids all across Chicago – they are nervous about their parents and nervous about their own safety because of the government and the rhetoric,” he said.