Tokyo will send about 100 soldiers to a remote Japanese island in the East China Sea amid growing anxiety over China's naval activities, a Japanese news report says.

The ground troops will be deployed on Yonaguni island, Japan's westernmost point, to carry out coastal patrols and surveillance of Chinese naval vessels, Jiji news agency quoted defence officials as saying.

Tokyo eventually plans to double the number of troops stationed on Yonaguni, which is roughly 100km east of Taiwan, the report said on Thursday.

Defence Minister Toshimi Kitazawa on Thursday stressed the importance of boosting defence in island areas, including Yonaguni, to a security committee meeting at the House of Representatives, Jiji reported.

The defence ministry has applied for Y30 million ($A363,000) from next year's budget for "preparatory research" on the issue, it said.