As she visited the HMAS Stirling naval base alongside her Australian and UK counterparts for the first time, Admiral Lisa Franchetti said the US would be there for its partners when it matters, where it matters.
As part of the AUKUS plan, US and UK nuclear submarines will rotate through HMAS Stirling, located on Garden Island south of Perth, before the site houses Australia's own nuclear submarine fleet.
But growing expectations of a second Donald Trump presidency and delays in the US submarine supply chain have fuelled concerns that Australia's military partners may not follow through on their commitment.
The commanders presented a united front on a visit to the HMAS Stirling base in Western Australia. (Richard Wainwright/AAP PHOTOS)
Betting markets have Trump odds-on to beat Democratic Vice-President Kamala Harris at the November poll, which could usher a return to isolationist policies after the 78-year-old withdrew the US from the Trans-Pacific Partnership in his first term in office.
But Admiral Franchetti hosed down those concerns.
"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," she told reporters on Tuesday.
"I am committed to delivering our part of AUKUS and really working with my teammates every day to make sure that ... we meet those key milestones to deliver AUKUS for our nations today, tomorrow and far into the future.
"I know that all of our partners know that we are going to be there for them when it matters, where it matters, and that's what we deliver every single day."
AUKUS is not under threat despite Trump once again indicating an America-first focus, says research director Jared Mondschein from the United States Studies Centre.
"It is Australia spending more money to do more of the burden-sharing in Asia, standing up to regional powers like China, and giving the US billions of dollars to expand the US defence industrial capacity," he told AAP.
Australia's navy chief, Vice Admiral Mark Hammond, was confident works to ready the base were progressing as planned.
"From what I've seen today and what we've been discussing this morning, HMAS Stirling is almost ready to go now," he said.
"If we had to mobilise this base to support nuclear powered submarines from Stirling tomorrow, all of the key building blocks are already in place.
"So I'm really confident that we will meet the timeline of the optimal pathway."
Meanwhile, the recently-elected Labour government has reaffirmed the UK's commitment to the alliance, with Defence Secretary John Healey saying it is "fundamental" to the nation's future security.
"The change of government through the election has meant no change at all in the United Kingdom's commitment to AUKUS," said UK Royal Navy Admiral Ben Key.
Earlier on Tuesday, Australia's Minister for Defence Industry Pat Conroy said the government would accelerate construction of the Army's new littoral fleet.
— Austal (@austal) @Austal was proud to host Minister for Defence Industry, The Hon @PatConroy1 MP at the Henderson, Western Australia shipyard today, where he announced that the build of 18 landing craft (medium) for the Australian Army is being accelerated.Minister Conroy was joined for the… pic.twitter.com/YskuQH7sHkJuly 23, 2024
As part of the $2 billion project, 18 medium landing craft will now be delivered in 2026, two years earlier than previously scheduled, while the delivery of eight heavy landing craft will be brought forward from 2035 to 2028.
The additional amphibious capability formed part of Australia's strategy of deterrence by denial, Mr Conroy said, along with the acquisition of long-range missile systems.
"Of keeping Australia safe by letting any potential aggressor know that we can strike them from longer distances, from multiple places," he said.
The vessels, which will enable troops and armoured vehicles to be deployed on beaches across the region, will be built by Austal at WA's Henderson Shipyard.