FILE - In this Jan. 30, 2017 file photo, U.S. Defense Secretary Jim Mattis, center, stands with Jordan's King Abdullah II bin Al-Hussein during an honor cordon at the Pentagon. Pyongyang will cast a decidedly dark shadow over U.S. defense secretary’s first trip overseas. Mattis is to make his debut with a visit to staunch U.S. allies South Korea and Japan, both of which host tens of thousands of American troops and, for good reason, see North Korea as their biggest national security threat. (AP Photo/Andrew Harnik, File)