A group of Japanese researchers has set sail for a remote islet on an expedition likely to exacerbate tension between Japan and China over disputed waters.

About 40 Japanese scientists are on their way to a tiny remote Pacific island on a journey with implications for China-Japan relations. The group, funded by the influential Nippon Foundation, a conservative philanthropic organization, left southern Japan on a 60-hour journey to Okinotori-shima.

China does not claim the territory, but it contends Okinotori-shima is just a big rock and thus does not merit being called an island under international law. That is an important distinction because if the outcroppings are not considered islands then China and other countries would have the right to explore for natural resources in what would be international waters.

Nippon Foundation spokesman, Hideo Fukuda, speaking from aboard the ship, insists the team is on a research mission and is not concerned with the dispute between Tokyo and Beijing. Mr. Fukuda says the researchers are focused on finding practical uses for the island and therefore need to gather data about the area, which has been little studied.

The island, some 1,700 kilometers southeast of the Japanese capital, is under the administrative jurisdiction of the Tokyo metropolitan government.

Tokyo Metropolitan Governor Shintaro Ishihara has pushed for exploitation of the island - asserting that if Okinotori-shima has commercial potential, then Japan's claim to extend its exclusive economic zone around the rocks would be strengthened.

Four-months ago, following repeated entries into the remote waters by Chinese vessels, Governor Ishihara requested that a Japanese fishing cooperative place nets and artificial fishing reefs near the island to further assert the exclusive economic zone claim.

Mr. Ishihara - an avowed nationalist - and others have also suggested building a lighthouse or a power plant on the tiny island.

Japan has also asked China to stop unannounced exploration missions in all Japanese exclusive economic zones.

The Japanese scientists, traveling on the research vessel Koyo-maru, plan to spend two days on the island after arriving on Sunday.