The Chinese military issued a warning to a U.S. Air Force B-1 bomber flying in the East China Sea Wednesday morning amid escalating tensions in the region, two U.S. officials told Fox News.

The Chinese said the U.S. bomber was flying in international airspace. American officials tell Fox News the bomber was flying in international airspace and continued on its mission---albeit without its wingman.

NORTH KOREA'S AGITATION GAME

Fox News has learned that two B-1 bombers were supposed to launch a patrol from Guam to the Korean Peninsula as part of training exercises with the South Koreans, hours after the failed North Korean missile launch.

Only one B-1 bomber was able to take off. The other was scrubbed due to maintenance issues.

The Chinese warning came over the emergency radio frequency known as "guard," according to one official. The incident unfolded when the American bomber was flying 70 miles southwest of the South Korean island of Jeju.

Meanwhile, Defense Secretary Jim Mattis and Chairman of the Joint Chiefs of Staff Gen. Joe Dunford were addressing lawmakers on Capitol Hill Wednesday about the defense budget and the current readiness crisis facing the U.S. military.