New York City Mayor Bill de Blasio said on Tuesday he intends to block ICE from entering public schools. The staff were directed to deny ICE agents entrance to schools unless executing a warrant signed by a judge and further detailed the procedure to be followed in the unlikely event ICE agents do show up with one.

He also said that he knows these things don’t take place — ICE agents entering schools—but at this point anything is possible. Immigration Customs and Enforcement have said they don’t intend to visit schools seeking out students who are in the United States illegally. Despite that fact, Mayor de Blasio blasted ICE for their recent crackdowns on illegal immigration by suggesting the agency has the potential to single out children.