Chicago Mayor Brandon Johnson hit back at President Donald Trump’s threats to send the National Guard to the city, calling the potential deployment of troops a “flagrant violation of the Constitution.”

“The city of Chicago does not need a military occupation. That’s not what we need,” Johnson said during a Sunday interview on MSNBC’s “The Weekend.” “We will take up legal action if necessary.”

Trump on Friday suggested that Chicago is the next city where he’d plan to intervene, and a Washington Post report on Saturday stated that the Pentagon had been planning a military deployment there for weeks.

Johnson and other state leaders, including Illinois Gov. J.B. Pritzker, have emphasized that they haven’t requested federal aid and that violent crime in the city is on the decline.

“The fact of the matter is violent crime is actually down in Chicago,” Johnson said on Sunday.