North Korea has reportedly fired a short-range missile from its coast into the Sea of Japan.
The Japanese defence and foreign ministries could not immediately confirm the report.
It would be the third time since late last month that North Korea has test fired such missiles.
On 7 June, North Korea launched two missiles with a range of about 100km off its coast. Other countries played down the tests, saying they were routine.
The latest tests come just after North Korea signalled it was ready to shut down its nuclear reactor under a six-nation deal.
US envoy Christopher Hill called on North Korea to act quickly on its promises to shut the reactor, saying the long dispute over frozen funds had been resolved.
Mr Hill said that Pyongyang at last received the blacklisted money it had demanded and said it should now shut down its Yongbyon reactor as it had promised.
