President-elect Donald Trump’s incoming border czar is putting New York City officials on notice that ICE will not hesitate to ramp up its presence in the Big Apple if the sanctuary city doesn’t cooperate with enforcing federal immigration laws.

Incoming border czar Tom Homan shared his determination to eliminate “sanctuary cities” from becoming “sanctuaries for criminals.” President-elect Donald Trump tapped the former Immigration and Customs Enforcement director to be his border czar on Sunday.

An ex-cop and former border agent from West Carthage, New York, Homan was appointed to the agency by former President Barack Obama in 2013. He famously pledged at the Republican National Convention in July that if Trump won the election he would “run the biggest deportation operation this country’s ever seen.”