President Donald Trump said Tuesday the U.S. would use the military to guard the southern border "until we can have a wall and proper security." Speaking during a lunch with Baltic leaders, Trump said the U.S. "cannot have people flowing into our country illegally, disappearing, and by the way never showing up for court." Trump said "we really haven't done that before," but President Barack Obama deployed National Guard troops to the U.S.-Mexico border during his administration.