China on Wednesday criticised a US decision to deploy up to 2,500 Marines to Australia as proof of a "Cold War mentality", in Beijing's strongest comments yet on the issue.

President Barack Obama announced earlier this month that the US would station the Marines in the northern city of Darwin in what many have viewed as a bid to counterbalance China's growing might in Asia-Pacific.

"We believe that any consolidation or expansion of military alliances is a manifestation of a Cold War mentality," defence ministry spokesman Geng Yansheng said in a statement.

It "does not conform with the current trends of peace, development and cooperation and is not conducive to enhancing mutual trust and cooperation between countries in the region".

Chinese state media has accused the US president of trying to win votes by using his diplomatic ambitions in Asia to detract from US economic woes.

Obama made the announcement as part of a week-long tour of the Pacific -- during which he also took in three summits -- aimed at asserting the United States as a Pacific power.

The US views with increasing concern China's growing assertiveness in Asia-Pacific on territorial disputes, as do many of the Asian powerhouse's neighbours.

But China maintains it has a policy of "peaceful development" with all countries.

Geng said he hoped "relevant parties will do more to help peace and stability in the Asia-Pacific region, rather than the opposite."