Trump floats "regular military" tackling crime with crackdowns in Chicago, NY

What he's saying: "I really am honored that the National Guard has done such an incredible job working with the police," Trump said during a press conference. "And we haven't had to bring in the regular military, which we're willing to do if we have to.

• "And after we do this, we'll go to another location and we'll make it safe also."

Zoom in: Trump said Chicago will be next, followed by New York, but he did not lay out a timeframe.

• Trump said he has not spoken to Chicago Mayor Brandon Johnson and slammed him as "grossly incompetent."
• "Chicago was our greatest city, actually," Trump said.

Zoom out: Trump also reiterated threats to declare a national emergency in Washington, D.C.

• "I could keep the troops here as long as I want," he said.

State of play: The Posse Comitatus Act prohibits the use of the armed forces to execute laws except in cases expressly authorized by the Constitution or a congressional act.

• It was enacted in 1878 to prevent U.S. Marshals from calling on the Army for assistance in enforcing federal law.

• The act is not a complete barrier if "the President determines that the use of the Armed Forces is required to fulfill the President's obligations under the Constitution to respond promptly in time of war, insurrection, or other serious emergency."

Context: Trump earlier this month previewed the other Democratic-led cities where he wanted to intervene.

• He singled out Oakland, California; Chicago; Baltimore; and New York City. Crime rates have dropped in recent years in all four

Go deeper: D.C. resists Trump's takeover — in court and on the streets

Editor's note: This story has been updated with additional details.