U.S. Southern Command posted a “flex” video just ahead of Trump’s announcement, which is expected to address military activity in the Caribbean.

Adding: from Flight Tracking from earlier this afternoon: 

A U.S. Air Force Bombardier E-11A BACN (reg. 22-9046) has been spotted flying over the Caribbean Sea at 41,000 ft, call sign BACN06, after departing Warner Robins AFB in Georgia.

The E-11A serves as an airborne communications node, linking U.S. and allied forces across land, sea, and air.