BEIJING (Reuters) - China rebuked U.S. Secretary of State Hillary Clinton on Monday for her public backing of Japan's administration over a string of uninhabited islands in the East China Sea which are at the centre of a messy dispute between China and Japan.

Clinton, speaking after meeting Japanese Foreign Minister Fumio Kishida, repeated the long-standing U.S. position that Washington acknowledged the islands were under Japan's administration, raising China's ire.

Chinese Foreign Ministry spokesman Hong Lei said on Monday that Clinton's remarks were a distortion of the facts.

"The relevant comments by the U.S. side neglects the facts and confuses right with wrong. China is extremely dissatisfied and resolutely opposed to this," he told a daily news briefing.

"We urge the U.S. side to take a responsible attitude towards dealing with the Diaoyu Islands, be cautious in what they say and do and take concrete steps to maintain regional stability and overall picture of Sino-U.S. ties to gain the trust of the Chinese people."

Tensions over the tiny islands, known as Senkaku in Japan and Diaoyu in China, have flared in recent months, one of several maritime territorial disputes involving China that have worsened as Washington seeks to shift its security focus to Asia.

Hong said nobody could change the reality that the islands belonged to China, though he insisted Beijing was committed to talks in resolving the spat.

"The source of the extreme tension over the Diaoyu Islands is because of Japan's illegal purchase (of them) and its series of actions which have escalated the situation. Nobody can conceal this."

The long-standing territorial dispute bubbled over again last September when the Japanese government decided to nationalize some of the islands, buying them from a private Japanese owner.

Clinton, who is due to step down in coming weeks, said the United States does not take a position on the ultimate sovereignty of the islands, but opposed any unilateral actions that would seek to undermine Japanese administration.

Japan's Chief Cabinet Secretary Yoshihide Suga said the Chinese remarks were "extremely regrettable".

"The comment by Secretary Clinton is a reflection of the United States' strong commitment to the Japan-U.S. security treaty. The Japanese government regards it highly and welcomes it."

(Reporting by Ben Blanchard; Additional reportin by Kiyoshi Takenaka in TOKYO; Editing by Michael Perry)