President Donald Trump has called Chicago “a mess” and threatened to tap the National Guard to tackle crime in the third-largest US city, expanding federal deployments beyond Washington, DC.

National Guard troops in Washington, D.C., have begun carrying firearms as former President Trump threatens to deploy troops to Chicago and Baltimore.

Northwest side residents called the plan a misuse of the military and a waste of money. Chicago officials described President Donald Trump's plan to deploy the National Guard as "unconstitutional."