TOKYO, Japan—The defense ministry is considering deploying troops on an island in the East China Sea near a group of islets that is claimed by Tokyo, Beijing, and Taipei, a ministry spokesman said Thursday.

"We are studying (the deployment) so that it could be included in the planned year-end revision of the basic defense program," the official said, confirming a news report on the plan to send an army unit to Yonaguni island.

Yonaguni is located 120 kilometers (75 miles) east of Taiwan and 170 kilometers south of the uninhabited islands known as the Senkaku in Japanese and Diaoyu in Chinese.

The ministry official said the location of military deployments along a chain of islands between the southern tip of Japan's Kyushu island and Taiwan is "an important factor in the nation's defense deployment."

The Tokyo Shimbun daily described the planned move as part of Japan's shift of its defense focus from its northern borders during the Cold War era to the country's southwestern borders.

Japan's current southernmost deployment of troops is in Naha on the main island of Okinawa, 500 kilometers northeast of Yonaguni, according to the defense ministry.