'The great nation of Australia': US President Donald Trump tweeted he would exempt Australia from tariffs.

A diplomatic onslaught to save Australian steel from Donald Trump's new tariffs appears to have paid dividends, with the US President signalling he will spare "the great nation of Australia" from the import levy.

Prime Minister Malcolm Turnbull spoke with Mr Trump on Saturday in what he described as a "very good and productive discussion" in which he reminded the President of the long-standing military ties between the US and Australia, as well as the "very fair and reciprocal" trade relationship between the two countries.

"I was very pleased the President was able to confirm that he would not have to impose tariffs on Australian steel and aluminium," Mr Turnbull later told reporters.

Mr Trump also tweeted about the phone call and indicated Australia would be spared the tariffs.