WASHINGTON (AFP) - United States (US) and Japanese officers are discussing worst-case contingency plans for retaking disputed islands in the East China Sea if China moves to seize them, US officials said on Wednesday.

Japan's Nikkei newspaper first reported the talks, which prompted a strong reaction from China.

"We have contingency plans and we discuss them with allies," a US official told Agence France-Presse on condition of anonymity, saying it was "natural" that the two governments would confer on worst-case scenarios given recent tensions.

A Pentagon official, who also asked not to be quoted by name, confirmed the discussions, saying "we're a planning organisation". But both sources said the US government did not want to fuel tensions and that the contingency planning would be only one of many topics on the agenda when top US and Japanese officers meet in Hawaii later this week.

Admiral Samuel Locklear, head of US Pacific Command, is scheduled to host General Shigeru Iwasaki, chief of staff of the Japanese Self Defense Forces Joint Staff, for talks on Thursday in Hawaii.

The Pentagon would neither confirm or deny if the contingency plans were under discussion.

"As a matter of policy, we do not discuss our military planning efforts," said Lieutenant Colonel Catherine Wilkinson.

"The US policy on the Senkaku Islands is long-standing. We encourage the claimants to resolve the issue through peaceful means," she said, using the Japanese name for the islands.

The US has made clear that its alliance with Tokyo applies to the islands, raising the possibility of American military action in support of Japan if China moves to seize them.

Beijing and Tokyo both claim the islands, known as Senkaku in Japan and Diaoyu in China.

The dispute has escalated in recent months, with Beijing repeatedly sending ships to waters around the islands to back up its claims. Tokyo has alleged that a Chinese frigate locked its radar on a Japanese destroyer in January.