The B-1B Lancers flew from Andersen Air Force Base in Guam to the East China Sea, linking up with Japanese fighters in what was the first time U.S. Pacific Command-directed Lancers conducted training with Japanese partners at night, according to the Air Force.
The training mission occurred the day before President Trump and Chinese President Xi met at the G-20 summit in Germany.
Flying over the East China Sea challenges China's Air Defense Identification Zone (ADIZ), a 200-mile airspace off the coast of China that requires aircraft to identify themselves.
The U.S. does not recognize China's ADIZ in the East China Sea. It does, however, recognize those of South Korea and Japan.
