Japan will carry on full-scale exploration for seabed resources, including rare metals, by maximizing the use of its exclusive economic zone so it can put the resources to practical use by around 2020, government sources said Sunday.

The plan is stipulated in the government's strategy on securing undersea resources, a copy of which Kyodo News obtained, and would be reflected in Japan's growth strategies, which might be approved by the Cabinet as early as June.

Based on the strategy, the government plans to explore for hydrothermal deposits, which contain rare metals, in 340,000 sq. km of ocean floor ranging from the median line between Japan and China to the Ryukyu islands in the East China Sea and east to the Izu-Ogasawara islands in the Pacific.

The project, however, may generate friction with China, which claims sovereignty over the Diaoyu, a chain of islands in the East China Sea that Japan calls the Senkaku islands.

The government also plans to explore an area off the coast of Shikoku for methane hydrate, an icelike compound that is expected to become a new source of energy, with an eye to putting the resource to practical use by around 2020.