Japan has lodged a protest with China after detecting what appears to be fresh test drilling for natural resources in an area near the two countries' median line in the East China Sea.
Japan and China agreed in 2008 to jointly develop gas fields in the region. While negotiations for a related treaty remain stalled, China has unilaterally been carrying out development activities, including building structures near the median line.
Japan's Chief Cabinet Secretary Yoshihide Suga told reporters on Thursday that a protest had been made through diplomatic channels.
Suga said the government has confirmed that a Chinese drilling vessel had been moved from its previous location and was engaged in what appeared to be test drilling at a new site in late January. The activities have been conducted on the Chinese side of the median line.
Suga said it is extremely regrettable that China is advancing unilateral development despite Japan's repeated requests to stop. He noted that Japan and China have yet to establish a maritime boundary in the East China Sea.
Suga also said the government intends to urge China to swiftly resume talks on the joint development of natural resources.