President Trump announced in a Wednesday morning tweet that transgender people will not be allowed to serve in "any capacity" in the United States military.

The U.S. military on Sunday shot down a Syrian Air Force fighter jet that bombed local forces aligned with the Americans in the fight against Islamic State militants, an action that appeared to mark a new escalation of the conflict. 

The Pentagon will send almost 4,000 additional American forces to Afghanistan, a Trump administration official said Thursday, hoping to break a stalemate in a war that has now passed to a third U.S. commander in chief.