North Korean leader Kim Jong Un announced plans in 2021 to develop technologically-advanced weapons, including hypersonic missiles.

South Korea’s Joint Chiefs of Staff (JCS) said the test took place at about 5.30am (20:30 GMT on Tuesday) and originated from the area around Pyongyang.

Japan also detected the launch with the Ministry of Defence saying the weapon reached an altitude of about 100km (62 miles) and flew east for more than 200km (124 miles).

A JCS official later told reporters on condition of anonymity that the military was considering the possibility that the weapon was a hypersonic missile, noting that it exploded in midair over waters off North Korea’s east coast.

The official told the Yonhap news agency that there appeared to be more smoke than during previous launches, raising the possibility of combustion issues. It also appeared to be a solid-fuelled missile, the official added.

The latest missile test came days after North Korea signed a comprehensive strategic cooperation treaty with Russia and as the US aircraft carrier Theodore Roosevelt arrived in Busan to take part in joint military drills with South Korea and Japan.

North Korean leader Kim Jong Un announced in 2021 that he wanted to modernise his country’s military and unveiled plans to develop a series of technologically-advanced weapons systems, including a hypersonic missile.

Such missiles are seen as harder to detect because they can travel at speeds in excess of five times the speed of sound and are designed to be manoeuvrable, posing a challenge to regional missile defence systems.

Pyongyang said in March that it had successfully tested a solid-fuel engine for a new-type intermediate-range hypersonic missile (IRBM), and the following month reported that Kim had overseen the test of that IRBM, which it named the Hwasong-16B.

Tensions in the region have risen as Kim has accelerated North Korean testing of missiles and other weapons. The United States and South Korea have responded by expanding their combined training and trilateral drills involving Japan, and sharpening their deterrence strategies.

North Korea, earlier this week, criticised the deployment of the Theodore Roosevelt and warned of an “overwhelming, new demonstration of deterrence”.

It has also been reinforcing its defences along the border with South Korea after suspending a 2018 military agreement with South Korea which was supposed to reduce tension. It has also sent more than 1,000 rubbish-filled balloons south in retaliation for balloons carrying leaflets criticising Kim’s rule that were floated to North Korea by activists.

For its part, Seoul has also suspended the military deal and resumed some propaganda broadcasts from loudspeakers along the border.