North Korea has defied its critics and launched its second long-range rocket this year. An official communique claimed the operation to put a satellite into orbit had been successful.
The international community believes the launch was a disguised ballistic missile test.
Japan confirmed the rocket had flown over Okinawa Island but said that its second stage had fallen into the sea some 300 km east of the Philippines.
Both South Korea and Japan immediately called meetings of their top security councils warning that they could not tolerate such action.
A similar rocket launch last April was aborted after less than two minutes flight. Pyongyang denies its is trying to develop technology to carry atomic warheads.
North Korea is banned from conducting missile and nuclear related tests under UN sanctions imposed after its 2006 and 2009 attempts.