Police forces across the US are already refusing to play any roll in president-elect Donald Trump's plan to deport more than three million undocumented immigrants after he threatened their budgets.

Following Trump's announcement of the plan in his first televised interview since the election Sunday (13 November), local law enforcement in Los Angeles, Denver, and the state of Massachusetts have all said Trump must rely on US Immigration and Customs Enforcement (ICE).

"We are not going to engage in law enforcement activities solely based on somebody's immigration status," said Los Angeles Police Chief Charlie Beck on Monday. "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."

Beck was just one law enforcement official who spoke out after Trump told 60 Minutes presenter Lesley Stahl that he would go after "people that are criminal, have criminal records, gang members, drug dealers." Trump estimated there are two to three million undocumented immigrant criminals in the US and said "we're getting them out of our country or we're going to incarcerate."

During president Barak Obama's two terms ICE figures show 2.8 million illegal immigrants, many of them convicted criminals, were deported from the US. According to an ABC News report Obama "deported more people than any other president's administration in history."

Trump was vague on the details of his plan in terms of time frame and exactly what it would involve. But he has said he intends to triple the number of ICE agents. The president-elect has also said he will cut federal funding for cities (that includes funding for police forces) that don't enforce national immigration law.

He also said he would "end catch and release", meaning anybody brought into custody as an undocumented immigrant will be deported. On Trump's campaign website he promises that on becoming president he will immediately "move criminal aliens out in joint operations with local, state and federal law enforcement."

But police in Massachusetts — including the cities of Boston, Chelsea, Cambridge, and Lawrence, along with state police — told the Boston Herald on Monday that their officers won't break the trust they've built with immigrant communities.

"We wouldn't be part of any effort of any kind of mass roundup," said Lawrence Police Chief Jim Fitzpatrick. "We encourage [immigrants] to not feel that their police department in any way shape or form is not there for them in times of crisis." The fear that was echoed by law enforcement around the state is that if people are undocumented that they wouldn't report crimes against themselves or others.

"Immigration enforcement is handled at the federal level, not by local law enforcement," Denver Police spokesman Doug Schepman said in a statement to local news outlets on the issue on Monday.

"The Denver Police Department has not participated in those enforcement efforts in the past," Schepman said, "and will not be involved in the future."