China says it's "strongly dissatisfied" with US Secretary of State Hillary Clinton issuing a veiled warning to Beijing not to challenge Tokyo's control of disputed islands at the centre of a bitter territorial row.
China is "strongly dissatisfied with and resolutely opposes" the remarks, Foreign Ministry spokesman Qin Gang said in a statement on the ministry's website on Sunday.
The maritime dispute, which has simmered off and on for years, intensified last year when the Japanese government nationalised islands in the small chain it did not already own, triggering angry responses in China.
China has since increased maritime and air patrols near the East China Sea territory, and in further escalations in recent weeks both Beijing and Tokyo have scrambled fighter jets, though there have been no clashes.
"We urge the US side to treat the issue of the Diaoyu islands with a responsible attitude," Qin said, referring to the territory by its Chinese name. Japan calls the islands the Senkakus.
He also called for Washington to be "careful in words, cautious in actions" and to take "realistic actions to protect the peace and stability of the region and Chinese-US relations".
Qin's statement came after Clinton on Friday said the US opposed "any unilateral actions that would seek to undermine Japanese administration" of the islands.
Clinton, speaking at a press conference with Japanese Foreign Minister Fumio Kishida in Washington, did not mention Beijing directly but said she wanted China and Japan to settle the issue peacefully.
"We do not want to see any action taken by anyone that could raise tensions or result in miscalculation that would undermine the peace, security and economic growth in this region," she said.
The US insists it is neutral on the ultimate sovereignty of the islands but also says they are under Japan's de facto administration.
China has persistently criticised the US position and Beijing's sending of maritime surveillance ships to the potentially gas-rich area is seen by experts as a way to contest the notion of Japanese control.
Complicating the issue is a security treaty that obliges the US - which keeps military bases in Japan - to aid the country in the event it is attacked.
Another factor that has raised tensions is the coming to power last month of hawkish Japanese Prime Minister Shinzo Abe, whose party won a landslide victory in elections.
Last week, state media said China will carry out a geographical survey of the islands and also reported that China's armed forces have been instructed to raise their fighting ability in 2013 with "the objective of being able to fight and win a battle".