President Donald Trump ridiculed New York City Mayor Bill de Blasio on Thursday for his decision to run for president in 2020.

Trump said that de Blasio was “considered the worst mayor in the U.S.”

“He is a JOKE, but if you like high taxes & crime, he’s your man,” Trump wrote. “NYC HATES HIM!”

De Blasio announced his campaign in a video on Thursday morning, celebrating important legislative accomplishments by raising the minimum wage to $15 an hour, paid sick leave, paid universal pre-Kindergarten, and pushing guaranteed health care.

But de Blasio also challenges Trump in the video. “I’m a New Yorker, I’ve known Trump’s is a bully for a long time. This is not news to me or anyone else here and I know how to take him on.”