Mayor Muriel Bowser opposes the federal plan to send over 500 law enforcement officials to tackle crime and homelessness in Washington

US President Donald Trump said on Monday he’s placing the Washington police department under federal control and deploying the National Guard to make the nation’s capital safer.

Trump has promised new steps to tackle homelessness and crime in Washington, prompting the city’s mayor to voice concerns about the potential use of the National Guard to patrol the streets.

Ahead of a news conference, Trump said on Monday on social media that the nation’s capital would be “LIBERATED today!” He said he would end the “days of ruthlessly killing or hurting innocent people.”

For Trump, the effort to take over public safety in Washington reflects a next step in his law enforcement agenda after his aggressive push to stop illegal border crossings. But the move involves at least 500 federal law enforcement officials, raising fundamental questions about how an increasingly emboldened federal government will interact with its state and local counterparts.