Two Japanese fighter jets and two US bombers conducted a joint exercise off the Korean Peninsula on Sunday.

The joint drill was conducted by two F-2 fighters of the Japan Air Self-Defense Force and two B-1 bombers of the US Air Force. Japanese Defense Minister Fumio Kishida said it was "part of the concrete action agreed by Japanese and US leaders at their summit meeting on May 26."

He also said that the drill was conducted under "the severe security situation including the DPRK's (Democratic People's Republic of Korea) latest missile launch," and aimed to further strengthen the deterrence and coping capability of the Japan-US alliance and show Japan's will and capacity to stabilize the region.

The DPRK on Saturday confirmed that it had successfully tested a second "Hwasong 14" intercontinental ballistic missile on Friday night, saying the rocket was meant as a "stern warning" for the US.

"North Korea remains the most urgent threat to regional stability," said General Terrence J. O'Shaughnessy, commander of US Pacific Air Forces, in a statement. "If called upon, we are ready to respond with rapid, lethal, and overwhelming force at a time and place of our choosing."