Australia is "right to worry" it will be slapped with tariffs on steel and aluminium by Donald Trump, the US president's former chief of staff says.
As the US prepares to impose a 25 per cent tariff on the materials from March 12, Mr Trump's former adviser Mick Mulvaney said protectionists have a greater influence within the White House in the president's second term in office.
Speaking at the Universities Australia Solution Summit in Canberra on Tuesday, Mr Mulvaney - who was chief of staff to Mr Trump during his first term - said while an Australian exemption was possible, concern remained.
"(The Republican Party) is much more protectionist than it was just 10 years ago, so ... you're right to worry about (tariffs being imposed)," he said.
"But ... the logic still applies, which is the stuff we buy from (Australia) we don't make (in the US), so there is no domestic industry to protect."
The comments come as Treasurer Jim Chalmers is in Washington to attend an Australian Superannuation Investment Summit before a meeting with US Treasury Secretary Scott Bessent.
Australian officials continue to lobby US counterparts for tariff exemptions, which were put in place during Mr Trump's first term.
However, the president's trade adviser Peter Navarro said Australia had been "killing" the US aluminium market following the first round of exemptions.
Mr Mulvaney said the trade adviser's opinion on tariffs carried a lot of weight in the White House.
"You're right to worry about Peter, he's a lot more influential now. He went to jail for the president. That counts in that White House," he said.
"I always thought Peter Navarro was crazy, but that's just me. But you're right to worry about it."
Former Australian ambassador to the United States Arthur Sinodinos said the views of Mr Navarro represented a threat to any Australian tariff exemption.
"Up until (Navarro's) intervention ... I thought up until that we would get the exemption. I'm not so sure now, because there's a strong faction in the White House that believes in tariffs," he told the universities summit.
"They also want, genuinely, to put tariffs up, particularly on China, but also for certain sectors, because that want to re-industrialise America."
Mr Sinodinos warned the impacts of the tariffs would force many countries, including Australia, to reconsider investment and trade options.
"While we obviously retain the US alliance and everything else, to what extent do we ... diversify our trade investment, just as we did when China was putting its economic and trade (measures) on us?" he said.
"That's what you need to do with an administration like this: you have to be confident. You have to be out there and say, look, there are new things we can do for mutual benefit."
