The North on Thursday launched two weapons from its east coast, with Japanese Prime Minister Yoshihide Suga calling them ballistic missiles.

Pyongyang is under multiple international sanctions over its weapons programmes, with UN Security Council resolutions banning it from developing ballistic missiles.

Biden told reporters that UN resolution 1718 "was violated by those particular missiles that were tested".

The firing was supervised by senior official Ri Pyong Chol, the official KCNA news agency reported, rather than leader Kim Jong Un.

It was successful with the two projectiles accurately hitting a target 600 kilometres (370 miles) into the Sea of Japan, known as the East Sea in Korea, it added.

The weapon could carry a payload of 2.5 tons, it said, in a dispatch that avoided using the word "missile".

Pictures in Pyongyang's official Rodong Sinmun newspaper showed grinning officers applauding after the launch from a vehicle, most of them not wearing masks.

The test was "of great significance in bolstering up the military power of the country", KCNA cited Ri as saying, "and deterring all sorts of military threats existing on the Korean Peninsula".