China launches aircraft carrier amid rising tensions with Japan Japanese protesters at an anti-China rally in Tokyo - relations have deteriorated since Japan bought the East China Sea islands. Photograph: Kim Kyung-Hoon/Reuters China has sent its first aircraft carrier into formal service in a show of naval ambition that could spur regional worries about territorial rows with Japan. China's ministry of defence said the Liaoning would "raise the overall operational strength of the Chinese navy" and help Beijing to "effectively protect national sovereignty, security and development interests." In fact, analysts say the carrier, refitted from a ship bought from Ukraine, will have a limited role and will be used mostly for training and testing ahead of the possible launch of China's first domestically built carriers after 2015. But China cast the formal handing over of the carrier to its navy as a triumphant show of national strength - at a time of bitter tensions with neighbouring Japan over islands claimed by both sides. Sino-Japanese relations deteriorated sharply this month after Japan bought the East China Sea islands, called Senkaku in Japan and Diaoyu in China, from a private owner, sparking anti-Japanese protests across China. "China will never tolerate any bilateral actions by Japan that harm Chinese territorial sovereignty," the vice-foreign minister, Zhang Zhijun, said on Tuesday. Japan must banish illusions, undertake searching reflection and use concrete actions to amend its errors, returning to the consensus and understandings reached between our two countries' leaders. The risks of military confrontation are slight, but political tensions between Asia's two biggest economies could fester. For the Chinese navy, the addition of carriers has been a priority as it builds a force capable of deploying far from the Chinese mainland. China this month warned the US, with Barack Obama's "pivot" to Asia, not to get involved in separate territorial disputes in the South China Sea between China and US allies such as the Philippines. The US secretary of state, Hillary Clinton, in turn urged China and its south-east Asian neighbours to resolve disputes "without coercion, without intimidation, without threats and certainly without the use of force." The timing of the carrier launch might be associated with China's efforts to build up patriotic unity ahead of a Communist party congress that will install a new generation of top leaders as early as next month. Narushige Michishita, a security expert at the National Graduate Institute for Policy Studies in Tokyo, said he thought the timing had nothing to do with the islands dispute. "China is taking another step to boost its strategic naval capability," he said. If they come to have an operational aircraft carrier, for the time being we are not super-concerned about the direct implications for the military balance between the US and Japan on the one hand, and China on the other. This is still not cutting edge. The East China Sea tensions with Japan have been complicated by the intervention in the dispute of Taiwan, which also lays claim to the islands. Japanese coastguard vessels fired water cannon to turn away about 40 Taiwan fishing boats and eight Taiwan coastguard vessels on Tuesday. Japan protested to Taiwan, a day after it lodged a complaint with China over what it said was a similar intrusion by Chinese boats. Taiwan has friendly ties with Japan, but the two sides have long squabbled over fishing rights in the area. China and Taiwan both argue they have inherited China's historic sovereignty over the islands. Japan's top diplomat, the vice-foreign minister, Chikao Kawai, was in Beijing for a meeting with his Chinese counterpart, Zhang Zhijun, in a bid to ease tensions. The flare-up in tension comes at a time when both China and Japan are confronting domestic political pressures. The government of the Japanese prime minister, Yoshihiko Noda, faces an election in a few months' time, adding pressure on him not to look weak on China, while China's Communist party is preoccupied with the leadership turnover, with President Hu Jintao due to step down.