Japan has opened a new monitoring station on an island about 60 miles off the coast of Taiwan, in a move likely to raise tensions with China, which disputes Japan's claims to several islands in the East China Sea.
Reuters reports that the radar facility was switched on Monday at Japan's Self Defense Force base on Yonaguni, the westernmost island in a chain that is controlled by Japan. Yonaguni lies 90 miles south of a disputed group of islands, known as the Senkaku islands in Japan and the Diaoyu in China.
"Until yesterday, there was no coastal observation unit west of the main Okinawa island. It was a vacuum we needed to fill," Lieutenant Colonel Daigo Shiomitsu, the commander of the base, told Reuters. "It means we can keep watch on territory surrounding Japan and respond to all situations."
The move is likely to anger the Chinese government, which has been increasingly assertive in the East China Sea as well as in the South China Sea, where it has been building artificial islands and has overlapping claims with several regional countries.
Protests broke out in Chinese cities in 2012 after Japan's government purchased three uninhabited islands from a private owner. The following year China announced a controversial air-defense identification zone, which runs almost up to the contested island chain.
Japan has responded by increasing its military presence on the islands. It plans to deploy missile batteries and increase troop numbers in the East China Sea by a fifth to 10,000 over the next five years, Reuters reports.