The self-proclaimed nuclear power North Korea has reported that it has made further progress in the development of long-range missiles with hypersonic warheads.

The missile authority successfully tested a medium-range missile with a new solid-fuel drive on Sunday, state media reported on Monday. The missile was loaded with a manoeuvrable hypersonic warhead. No details of the flight distance were given.

Both South Korea and Japan registered the test. South Korea’s military spoke of a suspected medium-range missile. It had flown around 1,000 kilometres before falling into the water in the Sea of Japan, which Korea calls the East Sea.

South Korea condemned the test as a clear violation of UN resolutions that prohibit North Korea from testing ballistic missiles of any range. Such missiles can be equipped with a nuclear warhead.

According to North Korean reports, the test was intended to demonstrate the gliding and manoeuvrability of a hypersonic warhead and the reliability of newly developed solid-fuel rocket engines.

The test was part of “regular activities for the development of high-performance weapon systems”, it was said. Solid-fuelled rockets give shorter warning time.

The communist leadership in Pyongyang has been pushing ahead with the development of nuclear-capable missiles for years. According to Pyongyang, it has also tested hypersonic missiles on several occasions.

Such weapons are particularly difficult to intercept as they reach more than five times the speed of sound and are manoeuvrable.

North Korea’s first missile test of the new year took place amid growing tensions on the Korean peninsula.

North Korea has significantly increased the scale of its missile tests over the past two years and stepped up its rhetoric against the US and South Korea. The two countries have expanded their military co-operation in response to Pyongyang’s rhetoric.