A US lawmaker on a Senate armed services sub-committee said more than a third of the steel and aluminium that went into ships and submarines came from partners including the UK and Canada, according to reports in Nine newspapers.
Both countries have been whacked by tariffs imposed by US President Donald Trump, giving rise to worries the cost of nuclear-powered submarines promised to Australia under the AUKUS agreement with the US and UK could become more expensive.
Mr Musk, who is spearheading the cost-cutting US Department of Government Efficiency, has been tasked with reviewing and helping to streamline the vessel procurement process.
But Prime Minister Anthony Albanese has brushed off concerns, noting he had spoken with former US president Joe Biden and members of the Congress and Senate during his last state visit.
"I'm confident about AUKUS," he told reporters in Darwin on Friday,
"I'm also confident that people, when they make an assessment, know that this is in Australia's national interest, but it's also in the national interest of the United States.
"We support the existing arrangements that we have with the United States."
Australian Strategic Policy Institute senior analyst Euan Graham said while the US-Australia military alliance was getting closer, there was more doubt and uncertainty politically.
"What it requires is a hard swallow in Canberra and a willingness to double down," he said.
"I don't just mean on AUKUS, but what the Australian Defence Force needs urgently is to get as much combat capability into service as soon as possible, given the security headwinds that we face globally and in the region."
Dr Graham said the "common complaint" of Australia relying on the US for its security, was down to inadequate defence spending.
"Australia has had a relatively easy, cheap ride on defence and that ride may be coming to a natural end now," he said.
"Not because it's been broken by American political dysfunction, but because we're in in a pre-war situation in this region."
Defence spending is about two per cent, and is set to rise to just above 2.3 per cent by the end of the decade with increased expenditure.
Under AUKUS, Australia is set to acquire three Virginia-class submarines from the US in the early 2030s, before a new fleet of boats is built for delivery from the 2040s.
But the US is lagging in production of the boats, and the American president can sink the deal if their own navy's capabilities are at risk.
Mr Trump has since announced a 90-day pause on tariffs above 10 per cent for most nations, apart from Canada, Mexico, and China.
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