"It is extremely disappointing that China is advancing in unilateral [gas field] development in the region, where the state border in the East China Sea has not been defined yet," Suga told journalists at a briefing in Tokyo, expressing dissatisfaction with oil output activities on the territory of the exclusive economic zones of Japan and China.
Japan and China have long disputed the boundaries of their exclusive economic zones in the East China Sea. They are also at odds over the territory that is referred to as the Senkaku Islands in Japan and the Diaoyu Islands in China.
In 2008, the two countries agreed to jointly develop hydrocarbon reserves in the East China Sea, but the talks halted in 2010 after a Chinese fishing boat rammed a Japanese coast guard vessel near the contested islands.
