Japan's attempt to seek support from other countries on the Diaoyu Islands spat with China is completely futile, a Chinese Foreign Ministry spokesman said at a regular press briefing on Monday.

Hong Lei made the remarks in response to a question concerning Japanese Foreign Minister Koichiro Gemba's visits to Britain, France and Germany this week.

Diaoyu Island and its affiliated islets have been an integral part of China's territory since ancient times, Hong said, noting that, regardless of its international propaganda, Japan can not deny the historical facts of its illegal theft and possession of China's territory.

The U.S. side said it would be impartial on the territorial dispute between China and Japan, Hong said, adding, "We hope the U.S. can keep its promise."