"We are aware of unconfirmed information of that nature. We are now trying to confirm it," said a spokesman for the Japan Defense Agency, referring to a report of a possible test-firing by Japan Broadcasting Corp (NHK) on its midday bulletin.

A foreign ministry official also said diplomats were not yet able to confirm the report.

"There is information that North Korea fired a missile this morning," NHK said in its midday bulletin, adding that it appeared to be the same type of missile as Pyongyang test-fired on Monday and presented no threat to Japan.

North Korea on Monday test-fired a surface-to-ship missile as part of its annual military exercise, South Korea's Joint Chiefs of Staff (JCS) said.

SPACE.WIRE