An apparent North Korean missile was seen landing at 170 km (106 miles) west of Japan's northern prefecture of Aomori, authorities said on Thursday.
The projectile, possibly a ballistic missile, came down at about 1544 hours (0644 GMT), Japan's Coast Guard said.
North Korea's latest missile launch is an "unacceptable act of violence", Japanese Prime Minster Fumio Kishida said on Thursday.
Kishida, who is in Brussels for the G7 summit, said he would like to confirm cooperation regarding North Korea's action at the meeting, adding that North Korea's missile technology was improving.
