U.S. Defense Secretary Jim Mattis, second from left, speaks during a meeting with China's Defense Minister Wei Fenghe at the Bayi Building in Beijing, Wednesday, June 27, 2018. (AP Photo/Mark Schiefelbein, Pool)

China's Defense Minister Wei Fenghe, left, and U.S. Defense Secretary Jim Mattis review an honor guard during a welcome ceremony at the Bayi Building in Beijing, Wednesday, June 27, 2018. (AP Photo/Mark Schiefelbein, Pool)

U.S. Defense Secretary Jim Mattis, center left, and China's Defense Minister Wei Fenghe stand together during a welcome ceremony at the Bayi Building in Beijing, Wednesday, June 27, 2018. (AP Photo/Mark Schiefelbein, Pool)

China's Defense Minister Wei Fenghe, center, and U.S. Defense Secretary Jim Mattis review an honor guard during a welcome ceremony at the Bayi Building in Beijing, Wednesday, June 27, 2018. (AP Photo/Mark Schiefelbein, Pool)

U.S. Defense Secretary Jim Mattis reviews a Chinese honor guard during a welcome ceremony at the Bayi Building in Beijing, Wednesday, June 27, 2018. (AP Photo/Mark Schiefelbein, Pool)