Japan Lodges Protest with China Over Gas Field Development in East China Sea

The Yomiuri Shimbun

17:13 JST, January 9, 2026

Japanese government has lodged a protest with the Chinese government through diplomatic channels regarding its new gas field development in the East China Sea, Chief Cabinet Secretary Minoru Kihara announced on Thursday.

The Japan Coast Guard had confirmed by Jan. 2 that a Chinese mobile drilling vessel had anchored in the area. The activities are taking place on the Chinese side of the median line between Japan and China.

In 2008, the Japanese and Chinese governments agreed to jointly develop gas fields straddling the median line between the two countries. However, China suspended negotiations, citing deteriorating bilateral relations, and has continued such activities as installing structures without permission.

The Japanese government is concerned that part of the gas field is connected to the Japanese side under the seabed, which could potentially deprive Japan of its resources.