U.S. Defense Secretary Jim Mattis plans to pay his first official visit to China in the spring, a senior Pentagon official said recently, the prospective trip coming as East Asia faces down North Korea's nuclear ambitions among a host of other security challenges."In the spring. That's where we're looking," Defense Department spokesperson Dana White said, in reference to what would be the first visit to China by a Pentagon chief in four years.During the planned visit, Mattis and senior Chinese officials are expected to discuss measures to rein in Pyongyang's nuclear and missile programs, as…READ FULL ARTICLE