North Korea's latest missile launch is a "further unacceptable violation" of its international obligations, a spokeswoman for the European Union foreign affairs chief said on Tuesday.

North Korea fired a missile that landed close to Japan in the early hours of Wednesday, the first test by Pyongyang since a missile fired over its neighbour in mid-September. The Pentagon said its initial assessment was that it was an intercontinental ballistic missile.

"This launch represents a further grave provocation, and a serious threat to international security," a spokeswoman for Federica Mogherini said.