The South Korean and US militaries have held a second joint air drill as a response to North Korea's launch on Friday of a new type intercontinental ballistic missile toward the Sea of Japan.

South Korea's Joint Chiefs of Staff announced the joint drill on Saturday.

Two US B-1B bomber, which the North is closely watching out for, joined the drills held that day. South Korea's F-35A jets and US F-16 fighters escorted the bomber.

The two militaries conducted an air drill on Friday just after North Korea launched its new ICBM. South Korean Air Force F-35A fighter jets attacked a mock mobile missile launch pads in the drill with laser-guided bombs.

The South Korean military says the two countries will work together closely to steadily improve their capabilities to respond to enemy provocations in the event of a contingency.

North Korea says on Friday morning it fired a Hwasong-17 from near the capital Pyongyang into the Sea of Japan.

The missile is believed to have reached a maximum altitude of around 6,000 kilometers and fallen into waters within Japan's Exclusive Economic Zone.