Japan has told China it will appeal to an international maritime court if Beijing starts gas production in a disputed field in the East China Sea, according to Japanese newspaper reports.
Japan's Foreign Minister Katsuya Okada told Chinese counterpart Yang Jiechi at a meeting last month that Tokyo would not shy away from appealing to the International Tribunal for the Law of the Sea, the Mainichi Daily News said, quoting diplomatic sources.
The two sides reached a broad agreement in 2008 on principles intended to solve the dispute by jointly developing gas fields, however, progress has been slow and Japan has accused China of drilling for gas in violation of the agreement, reports Reuters.
Tokyo objects to Chinese development of the Chunxiao gas field in seas close to Japan's claimed boundary.
Estimated net known reserves in the disputed fields are about 92 million barrels of oil equivalent, but there may be larger hidden reserves.