The tough talk from some Trump administration officials over tensions in the South China Sea has been dismissed as "stray voltage".
The possibility of a US naval blockade emerged following ramped up rhetoric in recent weeks from White House spokesman Sean Spicer and Secretary of State Rex Tillerson about denying China access to its artificial and militarised islands.
Former US defence official Amy Searight addressed a conference on US, Australia and Japanese strategic co-operation in Canberra on Monday and played down the shift away from cautious language.
"I would say this is more likely stray voltage of an early administration rather than strategy," Dr Searight told the conference at the Australian National University.
"I think we probably should reserve judgment until the administration gets its feet on the ground and gets fully up to speed on the issue."
China, Vietnam, the Philippines, Taiwan, Malaysia and Brunei have overlapping claims in the South China Sea.
The US has an interest in preserving freedom of navigation in the key trade route.
Meanwhile, former two-star Australian rear admiral turned-academic James Goldrick said there could be a silver lining from the uncertainty surrounding Trump's foreign policy direction.
"A little unpredictability might not always be a bad thing," he said, adding that Trump's unknown quality had brought some level of caution to China.
"It's quite clear there's an uncertainty and a desire in China to see how this is going to go, because China does fear doing something that could create catastrophic consequences."
US embassy political affairs counsellor John Hennessey-Niland was keen to offer reassurance about the new administration.
"I can assure you... US national interests do not change and it remains in the US interest to be a Pacific power," he said.
The Trump administration is yet to appoint a new ambassador to Australia.
Japanese ambassador Sumio Kusaka said ties between Tokyo, Canberra and Washington were key to peace and stability in the region.
"There is no room for complacency," he said.
Earlier on Monday, Prime Minister Malcolm Turnbull confirmed he discussed regional security with Mr Trump during a 25-minute weekend phone call.
