New York City Mayor Bill de Blasio (D) is threatening to sue the Trump administration in response to an executive order signed Wednesday to strip federal grants from "sanctuary cities," Politico reported.

“President Trump issued an executive order today and it's purported purpose was to enhance public safety, but here in New York City and in cities across this nation this executive order could in fact undermine public safety,” de Blasio said during a press conference at City Hall.

De Blasio said the “potential funding cuts suggested in the executive order would first and foremost fall on the NYPD."

There are "hundreds of American cities where this executive order could undermine public safety," he added. De Blasio also said the city would not "deport law abiding New Yorkers." ADVERTISEMENT He noted the executive order was "written in a very vague fashion" and therefore is "susceptible to legal challenges." "The minute any specific action to withhold funding were to occur, that’s when Zach Carter is in court the next hour," de Blasio said, referring to the city's corporation counsel.

President Trump on Wednesday signed an executive order that would strip federal grants from cities and states that do not enforce federal immigration laws.

De Blasio said Thursday on CNN that the New York Police Department has spent "decades building relationships with communities, including immigrant communities."

"This is the kind of thing that would destroy that progress and make it impossible for the police to keep cities safe," de Blasio told "New Day."

He said New York City has half a million undocumented people and the city wants them to come forward and talk to police if they witness or are a victim of a crime.

"If they believe by talking to a police officer, they will get deported and be torn apart from their family, they're not going to work with police," he said.