Australia urged China on Friday to refrain from the "militarisation of islands" to avoid a possible conflict, a day after the United States slammed Beijing for deploying missiles in the disputed South China Sea.
On Thursday China said that it had stationed weapons on one of the islands in the strategically important region, which US Secretary of State John Kerry said was evidence of an "increase of militarisation" and a cause for "serious concern".
Australian Prime Minister Malcolm Turnbull said that it was critical for the region’s prosperity that China and the US use international law to resolve their row.
"We urge all claimants in the South China Sea to refrain from any building of islands, any militarisation of islands, any land reclamation," Turnbull said in a joint press conference with New Zealand Prime Minister John Key in Sydney.
Turnbull also said during the conference that both Australia and New Zealand wanted to see a lowering of tensions while he urged Chinese President Xi Jinping to resolve all disputes in the seas through legal means.
"President Xi of China has said that one of China's biggest challenges is falling into what he calls the Thucydides Trap, which essentially is where a rising power creates anxiety among other powers such that conflict occurs," Turnbull said.
"If China wants to avoid falling into the Thucydides Trap, as President Xi describes it, then resolving disputes in the South China Sea should be done through international law, through all of those mechanisms that are available to us," he added.
Key said that Australia and New Zealand's two economic relationships with China, an important trading partner, would allow them to make their case against increasing tensions publicly and privately.
China claims nearly all of the South China Sea, through which one-third of the world's oil passes. Beijing has insisted that its island building is aimed at providing services including search and rescue facilities, but has also maintained that it has right to deploy necessary "self-defence" measures in the disputed area.
Other nations surrounding the sea - Brunei, Malaysia, the Philippines, Taiwan and Vietnam - lay claim to parts of it.
Australia and the US have conducted several so-called "Freedom of Navigation" overflights and sail-bys in the region, which China has described as "provocations."