Japan said yesterday that it needed to expand its surveillance activities to cover the Pacific Ocean off its east coast to protect its interests in a zone rich with resources where Chinese naval ships were recently spotted by ministry officials.
Japan's navy and coast guard have concentrated their efforts on the Sea of Japan and the East China Sea, off its west coast, where Tokyo is locked in a territorial dispute with Beijing over a group of East China Sea islets.
The islands, called the Senkakus in Japan and Diaoyus in China, are located near rich fishing grounds and potentially large oil and gas reserves. Uninhabited, they are administered by Japan and have become a theatre for cat-and-mouse operations by patrol vessels from both sides.
Chinese ships sailed through the disputed waters yesterday, Japan's coastguard said, before leaving the zone about three hours later. It was the first such incident reported in eight days.
Defence Minister Itsunori Onodera's comments followed observations by officials in July that Chinese naval vessels were sailing clockwise around Japan's main islands, through the Pacific Ocean, although no vessel entered Japan's territorial waters.
"Japan is the world's sixth-largest country in terms of the surface area of its exclusive economic zone," Onodera told a gathering of academics, journalists and military veterans.
"Many resources have recently been found at its bottom, not just oil and gas, but such things as platinum, rare metal and rare earth.
"So far, we have been conducting routine surveillance activities in such areas as the Sea of Japan and the East China Sea. When we think about our marine-related interests, we need to conduct surveillance over the Pacific Ocean as well."
As part of its move to fortify activities in the Pacific, the Defence Ministry has requested 450 million yen (HK$35 million) in its budget appropriation for the year starting April 2014 to build a facility on the remote island of Iwo Jima.
The facility would intercept wireless communications around the island.
Onodera restated his ministry's intention to look into the potential use of unmanned drones to bolster surveillance.