Bangkok: South-east Asian nations are turning to Australia to seek closer defence ties amid rising concerns over China's military build-up in the flashpoint waters of the South China Sea.

The move comes as the United States warned that a ruling of an international court in a case brought by the Philippines over its South China Sea claims in the coming weeks could trigger Beijing to declare an exclusion zone in the waters through which 30 per cent of world trade passes.

Foreign Minister Julie Bishop Credit:Alex Ellinghausen

Malaysia's Defence Minister, Hishammuddin Hussein, is scheduled to meet Australian Defence Minister Marise Payne next week to discuss China's placement of military equipment on disputed islands, in a sign that Malaysia is considering a tougher stand against Beijing, its largest trading partner.

"If the reports we've received from various sources regarding the build-up and placement of military assets in the Spratlys are true – this forces us in a pushback against China," Mr Hishammuddin said, adding he would also hold talks with the Philippines and Vietnam.