TOKYO, August 31 (RIA Novosti correspondent Andrei Fesyun) - Japan intends to reinforce two coral reefs in the Pacific Ocean in order to obtain legal ground to expand its exclusive economic zone, a Japanese official said Wednesday.

Ryutaro Yamamoto, a Japanese Fisheries Agency official, said the organization would request 400 million yen (about $3.7 million) from the state budget for the next financial year, beginning April 1, to study the possibility of reinforcing the coral reefs around the Okinotorishima islands, about 1,000km south of Tokyo. Some experts fear the archipelago has begun crumbling.

The Japanese coast guard is expected to receive another 34 million yen (about $300,000) to build a lighthouse on one of the islands.

China refers to the "islands" as separate rocks, which cannot be considered sovereign territory. Therefore, China has said Japan cannot call that part of the Pacific its exclusive economic zone.

A Chinese research vessel approached the archipelago within 200 nautical miles twice in 2004, which triggered protests from Japan.

Tokyo Mayor Shintara Ishihara, known for his nationalistic speech, visited the islands in May 2005 and hung a plaque reading "Okinotorishima, Japan" on a small rocky piece of land.