Australia would be expected to spend more on defence by a new Trump administration, the opposition says.
There would be "no free lunch" and Australia's defence contribution would come under increased scrutiny if the former president was re-elected, according to opposition defence spokesman Andrew Hastie.
The Liberal MP and former soldier recently returned from the US where he said the attempt on Trump's life has led to supporters "breaking cover" after "his fist pumps awoke the animal spirits".
"If Trump returns, there will be no free lunch," he told an Indian Ocean Conference in Perth on Thursday.
"We will be asked, what does Australia bring to the table? We will be expected to prove our worth, and step up our defence industrial commitments."
An AUKUS security partnership announced between Australia, the US and UK in 2021 involves Australia spending between $50 billion and $58 billion on three to five nuclear-powered submarines from the US.
Additional costs related to upgrading naval facilities and maintaining the vessels is expected to drive associated spending up to $368 billion.
Some of Mr Trump's rumoured policies would have "implications for Australia, and for AUKUS", Mr Hastie warned.
"We will need to spend more, spend sooner, and spend smarter. None of this is new, really," he said.
Defence Minister Richard Marles said on Wednesday AUKUS was secure regardless of the result of November's presidential election.
"Every engagement we've had with the Trump camp,with people on both sides of politics in America, there is support for what is playing out in relation to AUKUS," Mr Marles said.
US Navy chief Admiral Lisa Marie Franchetti addressed AUKUS' future while meeting with her UK and Australian counterparts in WA ahead of the conference.
"Regardless of who is in our political parties and whatever is happening in that space, it's allies and partners that are always our priority," Admiral Franchetti told reporters.
"I am committed to delivering our part of AUKUS."
Mr Hastie said his predictions came after reading The New Maga Deal by Peter Navarro, a former-Trump adviser jailed for contempt of Congress relating to the January 6 insurrection.
"A Trump Administration, according to Navarro, will be much tougher on trade partners and they will demand more of allies like Australia," Mr Hastie said.
"Navarro's book is not official policy. But regular Americans are buying it, and reading it. This has implications for Australia, and for AUKUS."
US President Joe Biden, who is not seeking re-election, is the last leader remaining in office of the three who announced AUKUS, following the exits of Scott Morrison and former UK prime minister Boris Johnson.
