China has asked Korea for support in seeking UN confirmation of its claim to the outer limits of a continental shelf that lies under the Diaoyu or Senkaku Islands disputed between China and Japan.
Diplomatic sources in Seoul said China notified Korea of plans to submit the request to the UN Commission on the Limits of the Continental Shelf.
When the Korean government decided in July to submit a request to the CLCS about its rights to a deep sea trench near Okinawa, China told Seoul that issues involving "overlapping continental shelves are of mutual concern." The diplomatic source said the recent Chinese move shows it is hoping to ally itself with Korea in dealing with the matter.
But it seems also aimed at stepping up pressure on Japan over the Chinese claim to the Diaoyu Islands.
The Korean government believes joining hands with China would bolster its negotiating power in talks with Japan. But others say Seoul should be cautious about siding with China at a time when relations in the region are brittle due to a cross-fire of territorial claims and other divisive issues.
Seoul, meanwhile, plans to submit documents to the CLCS supporting its rights to a 19,000 sq.km continental shelf that stretches until the deep sea trench near Okinawa. The shelf is part of a region south of Jeju that falls under joint jurisdiction with Japan and is equivalent to 20 percent of the size of the Korean Peninsula.
But Japan does not want Korea to join development of the area, which has vast underwater reserves of petroleum and natural gas.