The most prominent AUKUS sceptic in the Trump administration says the United States has been “very clear in private” with the Albanese Government about what is expected from Australia as part of the massive nuclear-powered submarine project.

Senior Pentagon official Elbridge Colby’s comments, that also highlighted the importance of Perth’s HMAS Stirling naval base, inset, come as The Nightly can reveal the Australian Submarine Agency recently held a ball in Canberra to celebrate its AUKUS successes.

During a tour of southeast Asia, the Department of War’s Under Secretary also declared the US was “optimistic” but “clear-eyed” about what was needed to be done to lift the production rates of Virginia-class submarines so boats can be sold to Australia.

Repeating President Donald Trump’s declaration last year that AUKUS was “full steam ahead” the Pentagon policy chief said there was a “very clear understanding” between partner nations on what was needed to deliver nuclear-powered submarines to Australia.

The Under Secretary for War did not directly answer when asked about the current production rate of Virginia-class nuclear submarines, which is languishing at about 1 to 1.2 boats a year, but needs to reach 2.33 to meet AUKUS requirements.

“We all know this is a historic endeavour on the part of both countries, but particularly for Australia, and that requires a real level of effort that we see the evidence for, and so we remain optimistic, but also clear-eyed, about what we all need to do to achieve that,” Mr Colby said.

“Obviously, there’s a lot of things that the Australian side needs to do. They know what is required.”

Asked about the strategic value of having US boats operating out of HMAS Stirling from next year, Mr Colby said the US was “pleased with progress” on Submarine Rotational Force-West, which is due to begin next year.

US officials last month sought urgent assurances from the Albanese Government over SRF-West after Defence Industry Minister Pat Conroy suggested the arrangement would be limited to five years.

“(It’s) tremendously important and is one of the key values that benefit not just the United States but Australia itself,” Mr Colby said in a phone hookup from Thailand.

“Australia really sees things through the lens of collective defence and a strategy of deterrence by denial, designed to sustain a balance of power in this key region. So we see a deep alignment of thinking”.

Colby did not directly answer when asked about nuclear-armed submarines at SRF-West after 2032 but said the US had a “very tight discussion and a very clear understanding” about AUKUS with the Australian government.

“They know what is required. We’ve been very clear in in private with them, you know, designed to give everybody a reasonable, stable, and realistic set of expectations to achieve this historic ambition that will put us all in a stronger place, and we’re hopeful that that that will continue.”

Elbridge Colby’s upbeat assessment on the progress of AUKUS comes just days after the Australian government agency responsible for acquiring nuclear-powered submarines held a gala ball in Canberra where staff received awards for their work.

At the event last Friday, Australian Submarine Agency boss Vice Admiral Jonathan Mead addressed the organisation and praised his staff for progress being made on the massive project.

Attendees at the celebration held at the National Arboretum have told The Nightly that numerous awards were given to ASA employees while the Royal Military College Band also performed, but the event has been criticised by the Greens.

“You have to wonder what they are celebrating, is it the US refusing to ever hand over a new Virginia submarine, or is it the countless millions they paid to consultants, because they sure aren’t celebrating building any boats,” Greens Senator and AUKUS critic David Shoebridge said.