China hits back at Japan, US over criticism of air defence zone A Japan Maritime Self-Defence Force surveillance plane flies over the disputed islands in the East China Sea. China has lodged formal complaints with the US and Japanese embassies in Beijing, expressing anger over criticism from both countries over its new air defence zone that has escalated tensions stemming from a territorial dispute in the East China Sea. China announced on Saturday that it would reserve the right to take military action in the form of "emergency defensive measures" if any aircraft strayed into its newly established "air defence identification zone" without authorisation. The area encompasses a wide area of the East China Sea, including regions very close to South Korea and Japan. Crucially, it covers eight uninhabited islands - claimed as Diaoyu by the Chinese and Senkaku by the Japanese - that have been central to a long-standing maritime dispute. Japanese Foreign Minister Fumio Kishida said on Sunday that Tokyo would refuse to recognise Beijing's claims to military rights over the new zone. He described China's announcement as a dangerous escalation that could lead to conflict. US Secretary of State John Kerry and Defence Secretary Chuck Hagel released statements criticising China's "unilateral" move that threatened to "destabilise" the region's status quo. But China's defence spokesman Yang Yujun said the reaction was "absolutely groundless and unacceptable." "We strongly require the Japanese side to stop all moves that undermine China's territorial sovereignty as well as irresponsible remarks that misguide international opinions and create regional tensions," he said. China's Foreign Ministry also said it had lodged "solemn representation" with outgoing US ambassador Gary Locke. Spokesman Qin Gang warned the US "not to choose sides" over the issue and to "make no more inappropriate remarks." China's announcement appeared to be the latest step in what analysts have called a long-term strategy to chip away at Japan's claims to control the uninhabited islands. Taiwan also lays claim to them. "Unlike his predecessors, [Chinese President] Xi [Jinping] is making foreign policy with the mindset of a great power, increasingly probing US commitments to its allies in the region and exploiting opportunities to change the status quo," the Asia-Pacific director at the US Institute of Peace, Stephanie Kleine-Ahlbrandt, said. China says the islands were unlawfully taken from it when Japan began its empire building in the late 19th century. But the territorial dispute flared last year, just before Mr Xi took power, when the Japanese government purchased three of the islands from a private Japanese owner. China's latest assertive stance on the East China Sea has been met with widespread support online from Chinese microbloggers. "This is the correct direction for China's strategic preparations," military analyst Yue Gang wrote on Weibo, a Chinese equivalent of Twitter. Clenching its fists together to make a breakthrough.