One of the United States' most senior navy commanders has said he would like Australia to carry out naval patrols close to territory claimed by Beijing in the South China Sea - a move that would provoke significant anger within the Chinese government. 
Vice-Admiral Joseph Aucoin, Commander of the Japan-based 7th Fleet, stressed the call was Australia's, but went further than any senior US defence figure in bluntly saying it would be valuable for other countries including Australia to challenge Beijing's assertiveness rather than leave it to the US.
Admiral Aucoin's remarks in Sydney come a week after it emerged that China has placed missiles on islands in the contested waters of the South China Sea. They also come ahead of the anticipated release of the Turnbull government's Defence white paper, which will focus heavily on building Australia's maritime power in response to the growing uncertainty in Asia provoked by China's rise.
Admiral Aucoin said he wished the challenge to Beijing's island-building and unilateral territorial claims in the strategically vital waters were not "portrayed as the US versus China" but rather that "all countries, no matter what the size or strength, can pursue their interests based on the law of the sea".
Asked whether that meant all countries with an interest in passage through those waters should be doing operations similar to the US's two recent "freedom of navigation" patrols close to Chinese-claimed territory, he said: "Personally, it's up to those countries but I think it's in our best interests to make sure those sea lines remain open and I'll leave it at that."
Asked then whether that could be interpreted as saying it would be valuable for Australia to do freedom of navigation operations within 12 nautical miles of China's claimed territory, he replied: "Yes."
Sailing within 12 nautical miles constitutes a challenge to territorial claims as this is the distance sovereignty extends from land into the sea.
Admiral Aucoin (pictured), who is visiting several cities including Canberra, said he was discussing the South China Sea with Australian counterparts but had "not specifically" discussed patrols within 12 nautical miles.
He is in charge of the two US ships that have so far carried out such patrols.
Admiral Aucoin also vowed that the presence of Chinese missiles on islands would not deter the US from continuing freedom of navigation operations.
"The scale and the speed of the reclamation of China has been alarming ... but ... we're going to sail, fly, operate in these waters and be prepared for any contingency."
About two-thirds of Australia's trade passes through the South China Sea.
Australia has long been pondering carrying out its own naval patrols within 12 nautical miles of territory that Beijing claims.
Labor's defence spokesman Stephen Conroy said the Turnbull government was hiding its lack of action behind "vague" language.
"Instead of waffle, the Turnbull government should be clear about whether it supports Australia conducting a freedom of navigation operation as a demonstration of our support for the international system in the South China Sea."
A spokesman for Defence Minister Marise Payne had not responded by deadline.