The South Korean government will submit an official document to claim the extended EEZ portion to the U.N. Commission on the Limits of the Continental Shelf (CLCS) by the end of this year, the Yonhap News Agency quoted an unidentified government official as saying.

"In order to submit an official document to the U.N. CLCS, the government is reviewing and processing related data," the official was quoted by Yonhap as saying.

In the document, Seoul is expected to claim that the Korean Peninsula's naturally extended continental shelf stretches to the Okinawa Trough in the East China Sea. It means the country's statutory EEZ stretches beyond the 200 nautical miles.

The disputed area in the East China Sea is believed to contain natural gas and oil deposits.

The government official was quoted as saying the formal claim to the U.N. commission this time is likely to prompt Beijing and Tokyo to take similar steps, reigniting fierce disputes among the Asian neighbors.