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 well as to expand military-to-military exchanges between Washington and Beijing.