Story highlights New York Mayor Bill de Blasio said, "We think it's very susceptible to legal challenge"

Trump signed an executive order that could block federal funding to sanctuary cities

(CNN) New York City Mayor Bill de Blasio said his city will use the courts to fight President Donald Trump's executive order to block federal funding going to "sanctuary cities," following executive action Trump announced Wednesday.

"We think it's very susceptible to legal challenge," he told CNN's Alisyn Camerota Thursday on "New Day." "If they make an attempt to pull that money, it will be from NYPD, from security funding to fight terrorism."





What are sanctuary cities, and can they be defunded?

"If an attempt is made to do that, we will go to court immediately for an injunction to stop it," de Blasio added. "We believe the executive order is vague and in some ways contradictory."

Trump signed Wednesday an executive order that he hopes will crack down and strip funding from "sanctuary cities," a term used for jurisdictions with policies that limit cooperation between or involvement with federal immigration enforcement actions.

The concept of sanctuary cities apparently originated in churches in the 1980s that were providing sanctuary to Central Americans fleeing violence in their home countries despite the federal government being reluctant to grant them refugee status.

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