The ruling Liberal Democratic Party proposed Friday that the issue of China potentially deciding to unilaterally develop natural gas fields in contested waters be taken to international tribunals.
An LDP task force asked the government to take the issue to the International Court of Justice or the International Tribunal for the Law of the Sea. The party is headed by Prime Minister Shinzo Abe.
A group of politicians submitted the proposal to Chief Cabinet Secretary Yoshihide Suga when they met at the prime minister's office, and the government's top spokesman told a press conference later in the day that Tokyo will consider the idea "from a strategic perspective."
The LDP task force said Japan should not accept attempts by Chinese state-run companies to develop seven new gas fields in the East China Sea, where the two countries have seen talks stall over joint development of other fields.
Beijing has repeatedly attempted to set up drilling facilities on its side of what Japan claims is the border of its exclusive economic zone, even though the undersea gas fields in the area could extend to Japan's side.
The call by the task force comes amid escalating bilateral tensions in the East China Sea over the uninhabited Senkaku Islands that Japan has controlled for decades but are claimed by China as Diaoyu, and by Taiwan as Tiaoyutai. Beijing recently established an air defense identification zone over the area that overlaps with Japan's.
The LDP lawmakers also said the government should enhance cooperation with the Philippines and Vietnam, which are engaged in territorial disputes with China in the South China Sea.