(NewsNation) — Ahead of a Donald Trump presidency, leaders in sanctuary cities insist they will not aid any mass deportation plans after Inauguration Day.

In states like Colorado, Illinois and New York, where hundreds of thousands of migrants have been bused from the southern border by GOP Texas Gov. Greg Abbott, officials have doubled down on their promise to protect newcomers.

Los Angeles became the latest city to approve sanctuary status after the City Council unanimously approved a measure this week.

The ordinance prohibits the use of city resources for federal immigration enforcement. It could also mean potential legal battles as the Trump administration prepares to use ICE and the military to carry out the campaign promise of mass deportations.

An estimated 1.8 million immigrants in the U.S. illegally live in California, more than any other state, with nearly a million in Los Angeles County. Los Angeles Mayor Karen Bass expedited the sanctuary city ordinance as resistance to Trump’s mass deportation plan.

In Chicago, where more than 50,000 new arrivals have been sent since 2022, Mayor Brandon Johnson has characterized Trump as a tyrant and says the city’s police force has enough work to do without assisting in apprehending immigrants convicted of serious crimes.

“We’re not going to bend or break or cower to someone’s threat,” Johnson told reporters after the election. “We’re going to stand up and unite around our shared values, and (residents) have my assurance that I’m going to protect the families of this city.”

Johnson previously targeted his anger at Abbott, who threatened to keep sending busloads of immigrants to cities like Chicago until the White House committed to securing the southern border.

But Trump and Tom Homan, the former acting director of Immigration and Customs Enforcement (ICE) and Trump’s “border czar,” are promising to withhold federal funding if Democrat-run cities don’t cooperate, leading some leaders in those places to push back even harder.

“Our city’s police department is not going to (double) as ICE agents — we’re just not going to do that,” Chicago’s mayor said. “It’s a dangerous precedent where members of communities begin to feel unsafe with their local police department.”

Chicago police declined to make anyone available for an interview with NewsNation.

In response to Democratic pushback in cities like Chicago, Homan has issued a warning.

“If you’re not going to help us, get the hell out of the way because we’re going to do it,” Homan told Fox News.

The standoff has created some backlash in Chicago, where Johnson’s stand to remain a welcoming city for immigrants isn’t shared by some other city leaders.

“We need those funds like you wouldn’t believe,” Alderman Anthony Napolitano told NewsNation. “The city is in so much disarray … it’s been catastrophic for the city of Chicago, and if you take away those federal funds, it’s only going to get worse for us here.”

The pushback against Operation Aurora

In Colorado, which Trump targeted during his presidential campaign over the presence of migrants and alleged migrant gang activity at an Aurora apartment complex, officials are also bracing for what could be coming.

Trump told supporters that he would deport violent criminals by sending “elite squads” of federal agents to “hunt down, arrest and deport” every single illegal alien. He called the plan “Operation Aurora,” referencing the Denver suburb.

Democratic Gov. Jared Polis told Colorado Public Radio that while he welcomes federal assistance in tracking down and apprehending immigrants who have been convicted of serious crimes or belong to gangs, the state’s support for Trump’s plans ended there.

“Obviously, it would devastate our economy and our society if someone were to come in and forcibly take our neighbors away from us,” Polis told the station.

As far as local police involvement in Trump’s proposed crackdown on immigrant criminals, Aurora’s police department says it will remain focused on dealing with local law enforcement.

“As we always have, we will work with our federal partners and follow federal law and directives as they apply to our community,” an Aurora city spokesman said in a statement provided to NewsNation.

Police in Denver, where around 45,000 migrants have been sent by Abbott since 2022, told NewsNation that it does not assist with the enforcement of federal immigration policy as part of city statutes. In addition, a department spokesperson said Denver police do not ask witnesses or victims of crime about immigration status, removing a potential barrier to reporting crimes and holding offenders accountable.

Tom Homan targets New York City’s approach

New York City Democratic Mayor Eric Adams has denounced Trump’s mass deportation plans for a city that has spent more than $5 billion in housing costs for the more than 200,000 migrants that have been sent there since 2022.

The New York Times reported that Manuel Castro, New York’s commissioner of migrant affairs, has vowed not to follow “the instructions of the federal government in cases of mass deportations.”

Like other sanctuary cities, New York has provisions in place to limit its participation with federal immigration enforcement. That doesn’t prohibit ICE from apprehending immigrants who reside in New York City but who are not U.S. citizens, the report said.

While ICE’s 287(g) Immigration and Nationality Act authorizes local police departments to deputize officers to assist with federal immigration enforcement efforts, the New York Police Department does not participate in those efforts, The New York Times reported.

Since 2014, the city has declined to honor ICE detention orders that would involve the city’s police department holding immigrants in the U.S. illegally who have been charged with crimes in custody until they can be picked up. However, under New York law, criminals who have been convicted of 170 serious offenses — including murder and rape — are not protected.

But Homan has pledged to send more federal agents to apprehend convicted immigrants in New York should city officials refuse to cooperate.

“We’re going to do the job,” Homan said in an interview with Fox News. “We’re going to do the job with you or without you.”