Obama on Monday urged President-elect Trump not to deport 'DREAMers' brought here as kids who 'did nothing wrong'

He previously called for going after 'bad hombres' here in the U.S.

Mayors of Los Angeles, New York, and Chicago vow to keep 'sanctuary' status where they don't turn over people to federal authorities because of their immigration status

The nation's three largest cities are vowing to maintain their 'sanctuary' status in defiance of President-elect Donald Trump's call to deport up to 3 million undocumented 'criminal' immigrants who came here illegally.

The chief of the Los Angeles Police Department said Monday the department had no plans of departing from its policy of not stopping people based on suspicion of their immigration status.

The mayors of LA and New York have said they maintain to keep their cities' 'sanctuary' status, and Chicago mayor Rahm Emanuel declared that the Windy City will 'always be a sanctuary city.'

All three cities are heavily Democratic and have large immigrant populations.

'To be clear about what Chicago is, it always will be a sanctuary city,' Emanuel said on Monday.

President-elect Donald Trump says a crackdown might deport two to three million immigrants who came here illegally and who have criminal records – but three top cities aren't planning to change the way they handle enforcement

After campaigning on a crackdown on illegal immigration, Trump told CBS' '60 Minutes' in an episode airing Sunday that he would focus on 'criminal' aliens first.

'What we are going to do is get the people that are criminal and have criminal records, gang members, drug dealers, where a lot of these people, probably 2 million, it could be even 3 million, we are getting them out of our country or we are going to incarcerate,' Trump said. 'But we're getting them out of our country, they're here illegally.'

Trump has listed immigration as one of his immediate priorities, although House Speaker Paul Ryan told CNN on Sunday: 'We are not planning on erecting a deportation force. Donald Trump is not planning on that.'

In 2014, the U.S. deported fewer than 200,000 criminal aliens.

Big city mayors Bill de Blasio and Rahm Emanuel are vowing to keep the role of 'sanctuary' cities

President-elect Donald Trump says as many as 3 million 'criminal' immigrants without documentation could be incarcerated or deported

Trump's statement drew an immediate backlash from three of the largest cities in America. In so-called sanctuary cities, members of law enforcement aren't required to report to the feds people who came here illegally when they come across them.

In New York, mayor Bill de Blasio is considering scrubbing the city records of people applied for city-issued ID cards, in what is being cast as an effort to keep the information out of the hands of the Trump administration, the New York Post reported.

'We are not going to sacrifice a half million people who live among us, who are part of our community,' said de Blasio, referencing immigrants living in the city. 'We are not going to tear families apart.'

In Los Angeles, police officers are prohibited from approaching someone to determine their immigration status, as the LA Times reported, and in practice don't hand people over to the feds for low-level crimes.

President Obama told reporters Monday he has urged Trump not to deport 'DREAMers' who got brought here by their parents.

Obama urged Trump to 'think long and hard before they are endangering the status of [people] who, for all practical purposes, are American kids,' Obama said. 'These are kids who were brought here by their parents. They did nothing wrong. They've gone to school, they've pledged allegiance to the flag. By definition, if they're part of this program, they are solid, wonderful young people with good character.'

He didn't directly respond at a White House press conference to a part of the question dealing with what would happen to data collected by the feds among applicants for a special status under Obama's executive order for people who were brought here illegally as kids.

About 728,000 people registered under the program, Bloomberg News reported.

LAPD chief Charlie Beck said Monday, following the release of Trump's comments: 'I don’t intend on doing anything different. We are not going to engage in law enforcement activities solely based on somebody’s immigration status. We are not going to work in conjunction with Homeland Security on deportation efforts. That is not our job, nor will I make it our job.'

It isn't yet clear whether a Trump administration, backed by a GOP Congress, could use the power of the purse to tug at sanctuary cities to bring them in line.

Trump has threatened to withdraw funds from sanctuary cities – something de Blasio called 'dangerous.'