Seoul suspects North Korea's failed launch aimed to test a hypersonic weapon.

According to South Korea, North Korea may have launched a hypersonic missile, as intelligence agencies investigate a failed ballistic missile test early on Wednesday. The test, reported by South Korea’s Joint Chiefs of Staff (JCS), occurred around 5:30 am (20:30 GMT on Tuesday) and originated near Pyongyang. Japan also detected the launch, with its Ministry of Defence stating the weapon reached an altitude of approximately 100km (62 miles) and flew eastward for over 200km (124 miles).

An anonymous JCS official informed reporters that the military is considering the possibility that the weapon was a hypersonic missile, noting its midair explosion over waters off North Korea’s east coast. The official mentioned observations of increased smoke compared to previous launches, suggesting potential combustion issues and indicating it was a solid-fuelled missile.

This missile test follows North Korea's recent comprehensive strategic cooperation treaty with Russia and coincides with joint military drills involving the US aircraft carrier Theodore Roosevelt in Busan, alongside South Korea and Japan. North Korean leader Kim Jong Un announced plans in 2021 to modernize the country’s military, including the development of advanced weapons systems such as hypersonic missiles, known for their high speed and maneuverability, posing challenges to regional missile defenses.

Pyongyang had earlier claimed successful tests of a solid-fuel engine for a new intermediate-range hypersonic missile (IRBM) in March, followed by Kim overseeing a test of that IRBM, dubbed the Hwasong-16B, the next month. The region has seen heightened tensions as North Korea accelerates missile and weapons testing. In response, the US and South Korea have increased joint training and trilateral drills with Japan, enhancing deterrence measures.

Earlier this week, North Korea criticized the deployment of the Theodore Roosevelt and warned of a new "overwhelming" demonstration of deterrence. It has also reinforced defenses along its border with South Korea, suspended a 2018 military agreement meant to ease tension, and retaliated against activists sending leaflets critical of Kim’s rule by sending over 1,000 balloons filled with rubbish southward.

In response, Seoul has suspended the military deal and resumed propaganda broadcasts via loudspeakers along the border.