Washington is pressing allies such as Australia and Japan to clarify what roles they would play in future wars, such as in Asia over the democratically governed island of Taiwan.
Elbridge Colby, a key Pentagon strategist, has confirmed the US is looking for allies to make clear their commitments in the event of potential conflicts.
"Of course, some among our allies might not welcome frank conversations," he posted on social media platform X.
"But many ... are seeing the urgent need to step up and are doing so."
Prime Minister Anthony Albanese said Australia's defence spending was about "advancing peace and security" in the region.
"Australia is through the AUKUS arrangements, providing considerable capacity, including increasing the capacity of the United States and the United Kingdom," he told reporters during a visit to China on Sunday.
He maintained Australia wanted to see the status quo remain in place for Taiwan, which Beijing considers part of its territory.
Mr Colby is leading the US review of its nuclear submarine deal with Australia under the AUKUS security agreement amid concerns not enough boats are being produced.
Acting Defence Minister Pat Conroy said "sovereignty would always be prioritised" in the nation's decision-making.
"The decision to commit Australian troops to a conflict will be made by the government of the day, not in advance," he said.
Australian National University expert associate Jennifer Parker said it was unlikely any federal government would give a "blanket agreement" to what the nation's contribution might be in the event of a conflict.
"What I suspect (the US is) probably asking for is a higher level of collaboration on war-gaming and scenario planning for various scenarios in the region," she told AAP.
"That allows allies working together ... to understand how each of the countries might respond.
"It is prudent for us to be sounding out what are the boundaries of the alliance relationship and what are the expectations."
The US is among 19 countries participating in Exercise Talisman Sabre, which began on Sunday and will involve 30,000 defence force personnel.
Mr Conroy said the exercise was expected to be closely monitored by China after the Asian power observed the last four since 2017.
"We will obviously observe their activities and monitor their presence around Australia, but we'll also adjust how we conduct those exercises," he said.
"People observe these exercises to collect intelligence around procedures, around the electronic spectrum and the use of communications."
Mr Albanese landed in Shanghai late on Saturday for a six-day tour that will focus on economic and security issues.
Defence analysts have flagged Mr Albanese will likely raise live-fire drills conducted by the Chinese military off Australia's coast earlier in the year after Beijing failed to notify authorities ahead of time.
But the government has refused to say whether the prime minister will raise the issue when he meets with Chinese President Xi Jinping during his second visit since taking the top job.
The Chinese flotilla also circumnavigated the country in a projection of power.
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