BEIJING (Reuters) - The Chinese Defense Ministry criticized on Wednesday the United States and Australia for upgrading their military alliance, warning that such steps could undermine trust in the region.

Chinese Defense Ministry spokesman Geng Yansheng offered the warning about the plan unveiled in mid-November by U.S. President Barack Obama and Australian Prime Minister Julia Gillard to establish a de facto base in north Australia for up to 2,500 U.S. Marines.

"Military alliances are a product of history, but we believe any strengthening and expansion of military alliances is an expression of the Cold War," Geng said in answer to a question about the U.S.-Australia announcement, according to a transcript on the ministry's website (

"This is not in keeping with the tide of the era of peace, development and cooperation, and does not help to enhance mutual trust and cooperation between countries in the region, and could ultimately harm the common interests of all concerned," he said.

(Reporting by Chris Buckley; Editing by Paul Tait)