Survey ship Koyo Maru, left, chartered by Tokyo city officials, sails around the tiny islands in the East China Sea called Senkaku in Japanese and Diaoyu in Chinese. Media reports say the Japanese government has agreed to buy the islands. (AP/AP)

Japan’s central government has agreed to buy a group of uninhabited islands that are also claimed by China and Taiwan, Japanese media reported Wednesday, potentially increasing regional tension over the simmering territorial dispute .

In a long-discussed deal, the central government will pay the Japanese family that owns the islands 2.05 billion yen ($26.2 million) for three of the islands in the East China Sea, the reports said.

A government spokesman refused to confirm the deal, which was widely reported by major Japanese dailies and the Kyodo news agency in articles that cited unidentified government sources. Japan’s government often briefs domestic reporters on background in advance of major decisions.

The nationalization of the hotly disputed islands, known as the Senkaku in Japan and Diaoyu in China, comes at a time when Japan’s government is struggling to maintain civil relations with its giant neighbor and placate increasingly influential nationalists who are wary of China’s rise.

Although this move may inflame already strained relations with China, Japanese Prime Minister Yoshihiko Noda intended it as a way to maintain relative calm, security experts say.

China responded to reports of the island purchase, saying it is monitoring developments closely and “will take necessary measures to defend its national territorial sovereignty.”

“We cannot help but ask where is Japan trying to lead China and Japan relations to,” Chinese Foreign Ministry spokesman Hong Lei said.

The Japanese central government purchase trumps a competing bid from the Tokyo metropolitan government, whose ultranationalist governor, Shintaro Ishihara, was raising money to buy the islands.

Ishihara has spoken about stationing members of Japan’s Self-Defense Forces on the islands and building harbors for fishing boats; such moves would raise the risk of confrontation with Chinese vessels that often roam the waters.

The central government, which has rented and administered the islands even before this purchase, prefers a hands-off approach. It keeps them uninhabited and almost always denies requests for permission for boats to land. Japan would maintain that no-
development policy after the purchase, which should be finalized by the end of this month, the Japanese news reports said.

“Our basic approach is to continue to maintain and manage the islands peacefully and stably,” Noda said at a news conference last month.

The islands — supposedly rich grounds for fishing and natural resources — have turned into a flash point in recent months, part of a regionwide escalation of territorial disputes that drew the attention of U.S. Secretary of State Hillary Rodham Clinton during her trip to Asia this week.

This summer, China sent three ships to the area. In response, Japan asked its ambassador to briefly return from Beijing. There were landings by activists from both sides. Anti-Japanese demonstrations broke out in numerous Chinese cities, with thousands taking to the streets. And last weekend, a group of Tokyo city officials and experts surveyed the islands without landing on them, measuring water depth, scouting locations for a dock anddeclaring that Japan’s territorial claim is “undeniable.”

Japan formally incorporated the rocky island chain as part of its territory in 1895; the United States administered the land after World War II but returned it to Japan in 1971.

Japan says China offered no objections at that time and raised its claim only several years later, amid news that the islands could have rich fossil-fuel reserves.

But a Chinese Foreign Ministry spokesman said the islands have been “China’s inherent territory since ancient times.”

In a Wednesday editorial in the China Daily, Jin Yongming, a maritime law expert with the Shanghai Academy of Social Sciences, wrote that Japan’s actions have “infringed on China’s territorial sovereignty and maritime interests and poisoned bilateral relations.”

“Japan is worried that China’s continued rise and the change in the regional power balance will end its illegal possession of the Diaoyu Islands,” Jin wrote, “and is thus eager to get an upper hand in the dispute.”

Liu Liu in Beijing contributed to this report.