Japan lodged a strong protest after confirming China's move to install a new structure on the Chinese side of the median line between the two countries in the East China Sea.

In a statement on Friday, Tokyo's foreign ministry said it is "extremely regrettable" that Beijing is advancing unilateral development in the East China Sea, when the exclusive economic zone and the continental shelf in the East China Sea have yet to be delimited.

Masaaki Kanai, director-general of the ministry's Asian and Oceanian Affairs Bureau, lodged a strong protest with Shi Yong, deputy chief of mission at the Chinese Embassy in Tokyo.

Japan has urged China to resume consultations on implementing a bilateral agreement on resource development in the East China Sea that the two sides reached in 2008.

According to Japanese daily Yomiuri Shimbun, the foreign ministry believes that the construction of what is set to become China's 22nd structure in the East China Sea is in connection to its gas field development.

Tensions between the two neighbors have escalated in recent months, particularly after comments by Japanese Prime Minister Sanae Takaichi in early November on a potential Taiwan contingency drew a strong reaction from China.