North Korea launched what appeared to be an intermediate-range ballistic missile (IRBM) from the Pyongyang area at about 6:53 am (2153 GMT on Monday) towards the East Sea, also known as the Sea of Japan, the general staff in Seoul (JCS) said.
According to the South Korean military the missile travelled some 600 kilometres before ending in the sea. Data on the missile test is being analysed in cooperation with the US and Japan, it said.
South Korea’s military assumed that the test was a medium-range missile with a range of at least 5,500 kilometres, which is less than that of intercontinental ballistic missiles (ICBMs).
South Korean news agency Yonhap cited the military as saying it did not rule out the possibility that North Korea may have tested a medium-range missile with a hypersonic warhead.
South Korea’s top command accused the largely isolated neighbouring country of another provocation.
In March Pyongyang said it conducted a ground jet test of a solid-fuel engine for a “new type” of intermediate hypersonic missile. The country spoke of a weapon system with strategic value, indicating that the missile could be equipped with a nuclear warhead.
Hypersonic missiles are particularly difficult to intercept as they reach more than five times the speed of sound and are manoeuvrable.
Japan’s government condemned the latest missile test by Pyongyang.
“This is a matter that concerns not only the security of our country but also the safety of the region and the international community. It is absolutely unacceptable,” said Prime Minister Fumio Kishida in Tokyo, according to the Japanese news agency Kyodo.
North Korea is prohibited by UN resolutions from launching or even testing ballistic missiles of any range. These are usually surface-to-surface missiles that can also be equipped with a nuclear warhead.
Tensions on the Korean Peninsula have again risen in recent months.