China says the US is putting regional stability in East Asia at risk following remarks by Defense Secretary Jim Mattis that an island group China claims falls under the US-Japan mutual defense treaty.

Chinese Foreign Ministry spokesman Lu Kang on Saturday called on the US to cease "making wrong remarks" over the issue.

Lu reasserted China's claim of sovereignty over the tiny uninhabited islands, known in Japanese as the Senkaku and Chinese as Diaoyu.

In a statement posted to the ministry's website, Lu said the US should avoid complicating the issue and "bringing instability to the regional situation." 

The US Defense Department quoted Mattis as telling Japanese Prime Minister Shinzo Abe in a meeting yesterday that their mutual defense treaty applied to all areas under Japanese administration, including the islands.