The US capital has a unique legal status as it is not a state and operates under a relationship with the federal Government that limits its autonomy and grants Congress extraordinary control over local matters.
Trump used this loophole to send the National Guard into Washington earlier this month to combat what he said was runaway crime and homelessness.
This week he boasted of a days-long streak without murders in the city and said he was also taking steps to beautify the capital, which is home to the White House, the US Capitol and other key institutions.
National Guard troops began carrying weapons in Washington last weekend.
Trump says he is considering similar moves for other Democrat-run cities including Chicago, New York and Baltimore.
– Agence France-Presse