On Friday, Japan’s Foreign Ministry lodged an official protest with China, accusing it of setting up 17 drilling rigs in a sector where the two countries’ economic zones overlap in the East China Sea.
“It is extremely regrettable that the Chinese side is unilaterally proceeding with development with the waters”, the ministry said.
“The borders of the economic exclusive zones and the continental shelf are yet to be settled in the East China Sea,” it added.
Japan considers that the median line between the coasts of the two countries constitutes the borders of their exclusive economic zones, but China considers that the border is closer to the coasts of Japan, basing this demarcation on the continental shelf of other characteristics of the ocean.
Tokyo and Beijing agreed in 2008 to jointly exploit gas rights in the disputed areas and suspend unilateral exploration, but the negotiations to determine how to implement the agreement were suspended two years later and have not resumed since then.