North Korea has issued notice of its plans to launch a satellite next month.
Yonhap news agency reports the launch would be from April 4 - 8 and that the first stage of the rocket would splash down in the Sea of Japan.
The second stage is to splash down in the Pacific Ocean.
The International Maritime Organization in London said it has been contacted about the plans, with details of dates, times and coordinates.
The agency said a notice would be issued to maritime vessels.
North Korea said it has also notified the International Civil Aviation Organization so it could inform aircraft.
The launch is to take place from an east coast site. The IMO says the tests are scheduled to take place during daylight.
Washington considers the launch to be a disguised long-range missile test.
Analysts say there are few technical differences between a satellite launch and a test of North Korea's longest-range ballistic missile, which uses the same rocket.
The missile, whose only previous test flight failed in 2006, is designed to fly as far as Alaska.
North Korea fired an earlier version of the rocket over Japan in 1998.