Morrison was speaking during a trip to Vietnam, one of China's most vocal critics over competing claims in the resource-rich sea. A Chinese survey ship has antagonised Hanoi since early July, sailing though waters near the Spratly Islands where Vietnam has several oil and gas projects. The ship left for a brief period this month and then came back - prompting irate calls from Hanoi to vacate the area it says falls within its Exclusive Economic Zone.
On Friday, Morrison said Australia supports "the principle of international law", without naming China and refusing to "take sides". "It is about ensuring that each and every nation in the region can have confidence in its own independence and sovereignty," he told reporters on his three-day trip.