North Korea fires ballistic missile into sea, ignores UN ban

North Korea ignored UN resolutions by firing a medium-range ballistic missile into the sea on Friday, Seoul and Washington officials said, days after its leader Kim Jong Un ordered weapons tests linked to its pursuit of a long-range nuclear missile capable of reaching the US mainland.

South Korea's Joint Chiefs of Staff said in a statement that the missile fired from a site north of Pyongyang flew about 800 kilometres before crashing off the North's east coast.

It was the first medium-range missile launched by the North since it fired two in April 2014, said a South Korean defence official, requesting anonymity citing department rules.

A senior US defence official said the missile appeared to be a Rodong type fired from a road-mobile launcher. The test violated multiple UN Security Council resolutions that ban North Korea from engaging in any ballistic and nuclear activities, said the official, speaking on condition of anonymity because he was not authorised to discuss the matter publicly.

The launch came as North Korea condemned ongoing annual South Korean-US military drills that it sees as an invasion rehearsal.

The two sets of drills are the largest ever, in response to the North's nuclear test and long-range rocket launch earlier this year. One of the drills, computer-simulated war games, was to end later on Friday while the other, field training, is to continue till late April.

In recent weeks, North Korea threatened pre-emptive nuclear strikes against Washington and Seoul and fired short-range missiles and artillery into the sea in apparent anger over the drills and tough UN sanctions imposed over its nuclear test and rocket launch.

South Korea's military said its surveillance equipment detected the trajectory of a suspected second missile fired from the same site. A Joint Chiefs of Staff statement said the object later disappeared from South Korean radar at an altitude of 17 kilometres and that it was trying to find out if a missile had been fired or something else was captured by the radar.

No fresh sanctions on the North were expected for Friday's launch. The UN Security Council slapped the country with sanctions each time when it conducted nuclear tests and long-range rocket launches, but it usually responded to short-range and medium-range ballistic launches with statements criticising them.