Earlier, the U.S. Indo-Pacific Command said four B-1 Lancers and two B-2 Spirit Stealth Bombers conducted bomber task force missions near the Korean Peninsula on Monday, the day before the U.S. and South Korea launched their annual joint summertime exercise, set to end Aug. 28.

Clark said such missions allowed the U.S. Air Force to train and exercise with its partners, "so that they are prepared to execute their mission as necessary."

He said he was not sure whether the U.S. will hold a joint bomber exercise with South Korea in the future when asked, but said its drills in the area will help prevent and prepare for any conflict in the region.

"I do know that it helps us to be a much more credible, capable force, not only from a conventional standpoint, but also a nuclear standpoint to provide that deterrent effect that we are after," he told the virtual meeting.