Trump says he will withdraw nomination of Musk associate Jared Isaacman to lead NASA NPR

The memo obtained by NPR says troops would be used in activities, including in "night operations and rural interdiction," as well as "guard duty and riot control" inside detention facilities.

Airlines and aviation regulators warned that flight disruptions are likely to continue even after the government reopens. Thousands of flights have been cancelled as air traffic restrictions ramp up.

Richardson, who previously served as U.S. ambassador to the United Nations, was also known for his volunteer efforts to free Americans held in foreign countries.