The central government announced plans Tuesday to strengthen patrols around the Senkakus Islands in the East China Sea by sending more large patrol ships, apparently to counter China's growing maritime assertiveness.

Under a new policy on guarding and managing the nation's remote islands, the government plans to send six large Japan Coast Guard patrol ships to the waters around the Japanese-controlled Senkakus, which are also claimed by China, where they are known as Diaoyu. The ships will begin patrols in the area by the end of March, and will join six vessels already patrolling there.

About 650 service members are expected to be assigned exclusively to the patrol activities, government officials said.

The central government has also decided to seek to register as state-owned properties some 280 uninhabited islands that have no landowners and that are within Japan's territorial waters.

It will also enhance its defenses around Okinawa's Yonaguni Island, Japan's westernmost territory, close to Taiwan, through the deployment of coastal observation personnel, officials said.

The policy was initially formulated in December 2009 by the government led by the Democratic Party of Japan to maintain waters managed by Japan, such as its exclusive economic zone. Last December, Prime Minister Shinzo Abe ordered a review of the policy.