Tension between China and Japan mounted on Monday over Beijing's unilateral move to establish an air defence zone over the disputed islands in the East China Sea, with both the countries summoning each other's envoys.
China also lodged protests with the United States and Japan for raising objections over its creation of the air defence zone, saying that its move was in line with UN Charter and will not affect civilian flights.
The diplomatic row erupted after the US said it would stand by Japan in any clash over the SenkakuIslands, which Beijing claims as the Diaoyus.
Assistant Chinese Foreign Minister Zheng Zeguang made solemn representations with US Ambassador to China Gary Locke, calling on the US side to immediately correct its mistake and stop making irresponsible accusations against China.
China summoned Japanese ambassador to express its strong dissatisfaction and solemn protest regarding Japan's unreasonable hype over China's establishing an air defence identification zone.
"It is completely unreasonable for Japan to make irresponsible remarks about China's establishing (of) an air defence identification zone," foreign ministry spokesman Qin Gang said.
Japan also called in Chinese ambassador to demand a rollback of the plan, which it said would interfere with "freedom of flight over the high seas."
Japanese Prime Minister Shinzo Abe denounced as a "profoundly dangerous act" China's designation of an East China Sea Air Defence Identification Zone, which covers most of that sea and includes the skies over a group of disputed islands.
But the Chinese foreign ministry said the zone is aimed at safeguarding China's national sovereignty and security of China's territory and air space.
"It is not directed against any specific country or target, nor will it affect the freedom of over flight in the related airspace," it said.
"The DiaoyuIsland and its affiliated islands are integral parts of China's territory. China resolutely defends its territorial sovereignty over the Diaoyu islands," the foreign ministry said.
"It is Japan's erroneous actions that have led to the current situation of the Diaoyu islands. The US should keep its words of not taking sides on the issue concerning the sovereignty of the Diaoyu islands and stop making improper comments," it said.
The move came as US Secretary of State John Kerry as well as the state department criticised the unilateral creation of the Air Defence Identification Zone in the East China Sea which they said would result in new tensions with Japan.
"The relevant measures by China are totally in line with the UN Charter and other international laws and practices, and thus are fully justified," the statement said.
"It is unreasonable and completely wrong for Japan to make irresponsible accusation against China's establishment of the Air Defence Identification Zone. This is what China is firmly opposed to," it said.
"With justice on the Chinese side, the Chinese foreign ministry and the Chinese embassy in Japan have refuted Japan's unjustifiable representations and urged the Japanese side to correct its mistakes," it said.
"I want to reiterate that the DiaoyuIsland and its affiliated islands are integral parts of China's territory. China is firm in its resolve and will to safeguard sovereignty over the Diaoyu islands. We call on the Japanese side to stop all actions that undermine China's territorial sovereignty and make efforts to properly manage and solve the relevant issues through dialogue and negotiation," Qin said.
Image: A group of disputed islands, Uotsuri island (top), Minamikojima (bottom) and Kitakojima, known as Senkaku in Japan and Diaoyu in China is seen in the East China Sea, in this photo taken by Kyodo.