On May 29, the North also informed only Japan of the plan to launch a satellite and two days later launched a military spy satellite, but the rocket crashed into international waters.

Japan's Coast Guard on Tuesday said North Korea informed it of the plan. Yet if it fails again, the satellite could fall into either the West Sea southwest of North Korea or the Pacific Ocean east of the Philippines, all outside of the Japanese exclusive economic zone.

North Korea has announced it will try to launch a spy satellite again between Aug. 24 and 31 after its earlier failure in May.

Earlier, North Korean state media claimed that leader Kim Jong-un watched the Navy test-fire a "strategic cruise missile," but none showed up on the radar here in recent days.

State media said on Monday Kim inspected a cruise missile test aboard a warship. They did not specify when the launch happened, but the Joint Chiefs of Staff here believe that it must have been between Aug. 14 and 18, when Kim was visiting a flood-heat area in nearby Anbyon, Kangwon Province.

The report came the same day South Korea and the U.S. launched massive Ulchi Freedom Shield military drills.

It claimed that the missile "rapidly hit a target without even an error." The ship's "regular posture for mobilization and offensive ability were verified."

But in a text message to reporters, the JCS dismissed the report, calling it "exaggerated and different from the facts in many aspects."

According to the JCS, the missile was not a strategic cruise missile as the North claims, but merely a ship-to-ship missile which "has a short range and is not a great threat."

It also failed to hit the target, the JCS said. Pictures provided by the state media show only the launch but not the impact, whereas the regime is not normally shy to publicize its successes in some detail.