Golfing legend and Donald Trump mate Greg Norman was "called in" to lobby the US President on Australia's behalf over steel tariffs, Foreign Minister Julie Bishop has confirmed.
Mr Norman was among a number of senior business leaders to petition Mr Trump in a letter reminding him of the US's trade surplus with Australia, as well as the two countries' long-standing defence ties.
Ms Bishop on Friday said she was aware of the letter and the government would spare no effort in trying to convince President Trump to exempt Australian steel from a 25 per cent tariff.
"We’re calling in all contacts at every level. This is a very important matter for Australia, it’s also a very important principle," she told the ABC's AM program.
"We’re making contacts at every level throughout the administration, including business representatives, to make our case."
Ms Bishop said she had personally "spoken to very close business contacts of the President here in New York" to get them to lobby Mr Trump.
News Corp chief executive Robert Thomson and Dow Chemical boss Andrew Liveris, both Australians based in the US, reportedly signed the letter, as did former US ambassador to Australia John Berry.
Mr Norman is a good friend of Mr Trump's, bonding through a mutual passion for golf. When Mr Trump won the presidency, Australian ambassador to Washington Joe Hockey called Mr Norman on behalf of Prime Minister Malcolm Turnbull to find out Mr Trump's mobile phone number.
"I don't normally give out cell phone numbers of people in my database, but considering it was for the Prime Minister to call the President of the United States, I thought that would be the right thing to do," Mr Norman later explained.
Mr Trump signed the tariff orders on Thursday but gave exemptions to Canada and Mexico, and afforded close US allies 15 days to negotiate possible carve-outs.
The White House said US allies would need to find alternative ways to "address the threatened impairment of the national security caused by imports from that country", according to The New York Times.
Once the tariffs come into force in 15 days, levies on steel imports will rise by 25 per cent, while aluminium will be subject to a 10 per cent rise.
Ms Bishop said Australia was "very much" focused on gaining an exemption. "We'll continue to push our case, we'll continue to advocate on behalf of Australia for as long as it takes," she said.
The Foreign Minister said the US was entitled to make its own trade policy but confirmed the Australian government had been given assurances last year by the President himself that tariffs would not apply to Australia if they were implemented.
"We understood that Australia would be exempted if the United States would go down that path," Ms Bishop told the ABC.