China Tuesday condemned Japan's registration of one of the four islands near the Diaoyu Islands in the East China Sea as its national asset, slamming Tokyo's move as "unlawful and invalid."
"Any unilateral move surrounding the Diaoyu Islands and its adjacent islets taken by Japan is unlawful and invalid, and cannot change the fact that the islands belong to China," foreign ministry spokesperson Hong Lei said.
"China will continue to take necessary measures to firmly safeguard sovereignty over the Diaoyu Islands and the affiliated isles," Hong said, reiterating that the Diaoyu Islands and other affiliated isles have been an inherent part of Chinese territory since ancient times, and China holds indisputable sovereignty over them.
Japan's Chief Cabinet Secretary Osamu Fujimura announced Monday that one of the four islands near the Diaoyu Islands had been registered as a national asset by Tokyo.
Japanese officials said the registration is unlikely to be applied to the three other islands because "they are owned by civilians," the Kyodo News Agency reported.
Last August, Tokyo placed 23 uninhabited islands under state control, but the four islands near the Diaoyu Islands were exempted out of consideration for China, Kyodo added.
Liu Jiangyong, a deputy director of the Institute of International Studies at Tsinghua University, told the Global Times that Japan's move is part of its recent efforts to further demonstrate its territorial claims in the area.
"It can also be viewed as a probing activity to test Beijing's reaction, as Japan might try the same trick to register other islands in the area as its state assets in the future," Liu said.
The latest move came after Tokyo named 39 isolated, uninhabited islands earlier this month, including some of the Diaoyu Islands, which already drew strong objections from China.
On the following day, China's State Oceanic Administration released standard names and descriptions of the Diaoyu Islands and its affiliated isles.
On March 16, a Chinese maritime surveillance fleet consisting of two patrol vessels arrived in waters near the Diaoyu Islands for a regular patrol, but was followed by a Japan Coast Guard patrol ship.
Despite tensions, Liu said territorial disputes between China and Japan are still manageable.
"We might witness more confrontations between maritime units of the two countries in the waters near the Diaoyu Islands due to reinforced surveillance efforts by both sides, but the use of force is unlikely," Liu said.