Cuts to the production of a nuclear-powered submarine in the US have raised concerns about Australia's planned acquisition as the government moves ahead to regulate its nuclear industry in preparation.
A Virginia-class submarine has been cut from the 2025 proposed US defence budget.
The US is set to sell Australia at least three, and possibly five, second-hand Virginia-class subs in the early 2030s, raising concerns that cuts to its production could hamper Canberra's planned acquisition.
But Australia, the US and UK remained committed to the AUKUS pact under which they would be delivered, Defence Minister Richard Marles said.
"All three AUKUS partners are working at pace to integrate our industrial bases and to realise this historic initiative between our countries," he said.
US President Joe Biden's budget request for 2025 also includes US$11 billion for additional investment over the next five years for the domestic submarine industry.
Australia will also contribute $3 billion to the US submarine industry to help increase production rates.
Australia was completely dependent on Washington to acquire the submarine and America would always back their navy if there was a shortage in production, former prime minister Malcolm Turnbull said.
"The reality is the Americans are not going to make their submarine deficit worse than it is already by giving or selling submarines to Australia and the AUKUS legislation actually sets that up," he told ABC radio on Wednesday.
The AUKUS pact, which would underpin Australia's military for decades to come, would go through peaks and troughs, Opposition Leader Peter Dutton said.
"But they will be ironed out because, in the end, our three countries coming together make us stronger than if we stand apart," he said.
Virginia-class submarines supposed to be delivered this year in America were running an average of more than 30 months late, US defence under secretary comptroller and chief financial officer Michael McCord said.
Money not flowing through to the industrial base fast enough was also a problem, Mr McCord said, as he pointed to there being more than a dozen on order that remained in production.
Spending money to prop up industry rather than spending it on another submarine was a smarter investment, he added as America pushed to boost the production rate to two submarines a year.
Rank and file Labor members have come out against the AUKUS agreement, questioning why Australia would send billions of dollars to prop up the US production line.
Labor Against War branded the US budget cut to the Virginia-class a "potential lethal blow to AUKUS".
Clarity was also needed about the role an independent nuclear watchdog in Australia would play when it came to acquiring the technology from the US, the Royal Institution of Naval Architects said.
This was especially pertinent when overseas construction involved the part of the submarine that would contain the nuclear reactor, the Australian division's secretary Robin Gehling said.
"It needs to be made more clear as to where the jurisdiction of the regulator starts along that supply chain," he told a parliamentary hearing assessing how Australia would regulate nuclear technology on Wednesday.
The hearing was told that any part of the nation could be declared a designated zone, and could be used for storage of nuclear waste.
Department of Defence Deputy Secretary Governance John Reid said the legislation was intended to provide flexibility for future government decisions that may be made.
He said there wasn't a reference to Indigenous people, or the prospective impact on their land in the bill.
