US-Japan-South Korea joint military exercise after North Korea missile test. (Source: Reuters)

The joint exercise follows North Korea's launch of an intercontinental ballistic missile (ICBM) on October 31.

The South Korean military said the trilateral US-Japan-South Korea drills took place in waters east of Jeju Island, south of South Korea, in response to North Korea's test-launch of the Hwasong-19 ICBM last week.

During the drills, fighter jets from South Korea, the United States and Japan escorted US heavy bombers in the area where South Korea and Japan's air defense identification zones overlap. The drills also included the heavy bombers attacking a simulated target to demonstrate their "overwhelming" capabilities, according to the South Korean Joint Chiefs of Staff (JCS).

The exercise involved US B-1B nuclear bombers, South Korean F-15K and KF-16 fighters and Japanese F-2 jets.

This is the second air force exercise between the three sides this year, amid joint efforts to strengthen trilateral security cooperation against North Korea's growing nuclear and missile threats.

North Korea’s ICBM test last week was the first time Pyongyang has launched a long-range ballistic missile this year, demonstrating progress in its missile program. Observers said the missile flew higher and farther than any previous missile.

North Korean leader Kim Jong Un called it a "appropriate military action" to counter external security threats posed by its rivals.