The leader of the Democratic People's Republic of Korea, Kim Jong Un, has declared Wednesday's test launch of a ballistic missile the "greatest success".

According to South Korea's military, the missile was fired from a submarine submerged off the northeastern port of Sinpo. It flew 500 kilometres towards Japan, exceeding previous sub-launched tests. The United Nations has condemned the launch, which appears to indicate an advancement in Pyongyang's nuclear strike capability.