Australian Prime Minister Malcolm Turnbull on Wednesday called China's military deployments on the South China Sea "counterproductive," an unusually forceful rebuke against the country's biggest trading partner.

Australia has consistently supported U.S.-led "freedom of navigation" activities in the South China Sea, where Beijing has been adding reclamation to islands and reefs in waters claimed by several regional countries.

The United States has accused China of raising tensions in the South China Sea by its apparent deployment of surface-to-air missiles on a disputed island, a move China has neither confirmed nor denied.