TOKYO/BEIJING - China said it would not tolerate provocation after Japan's top government spokesman said on Tuesday Japan might station government workers on disputed islands in the East China Sea to defend its sovereignty.
Relations between the world's second- and third-biggest economies have been strained over the uninhabited isles which Japan controls but both countries claim. The isles are known as the Senkaku in Japan and the Diaoyu in China.
A year ago on Wednesday, the Japanese government bought three of the isles from a private owner, inflaming anger in China where there were big anti-Japan protests over the purchase.
Aircraft and ships from the two countries have played cat-and-mouse in the vicinity of the islands ever since, raising fears of conflict, perhaps sparked by an accident.
Japan's Chief Cabinet Secretary Yoshihide Suga, speaking on the eve of the anniversary, said it was "extremely regrettable" that Chinese government ships had repeatedly entered what he described as Japan's territorial waters.
The government was making "resolute but calm responses to defend our territory, territorial waters and airspace decisively", he said, adding: "Our country will never make a concession on the matter of sovereignty."
Asked if Japan might station government workers on the islands, Suga said: "That is one option".
Chinese Foreign Ministry spokesman Hong Lei expressed "serious concern" about those remarks.
"The Chinese government has an unshakeable resolve and determination to protect the country's territorial sovereignty and will not tolerate any provocative acts of escalation over China's sovereignty," he told a daily news briefing.
"If the Japanese side recklessly makes provocative moves it will have to accept the consequences."
Relations between the neighbours have been soured for years by what Beijing says has been Tokyo's refusal to properly atone for wartime atrocities committed by Japanese soldiers in China between 1931 and 1945.