The president, speaking to reporters on Air Force One on his way to the NFL Super Bowl in New Orleans, said he would announce the new metals tariffs on Monday.
He also said he would announce reciprocal tariffs on Tuesday or Wednesday, to take effect almost immediately, applying them to all countries and matching the tariff rates levied by each country.
"And very simply, it's, if they charge us, we charge them," Trump said of the reciprocal tariff plan.
It's not yet clear how and if Australia, which exports around $US300 million ($A479 million) worth of steel and a similar amount of aluminium to the US a year, will be affected.
The Australian government has recently argued that the country has a trade deficit with the US, and that should be taken into consideration.
During the first Trump presidency, Australia was given an exemption from such tariffs based on that argument but if tariffs are imposed, the flow-on effect for its producers could be challenging.
The largest sources of US steel imports are Canada, Brazil and Mexico, followed by South Korea and Vietnam, according to government and American Iron and Steel Institute data.
By a large margin, hydropower-rich Canada is the largest supplier of primary aluminium metal to the US, accounting for 79 per cent of total imports in the first 11 months of 2024.
"Canadian steel and aluminium support key industries in the US from defence, shipbuilding and auto," Canadian Innovation Minister Francois-Philippe Champagne posted on X.
"We will continue to stand up for Canada, our workers, and our industries."
Trump also said that while the US government would allow Japan's Nippon Steel to invest in US Steel, it would not allow this to become a majority stake.
"Tariffs are going to make it very successful again, and I think it has good management," Trump said of US Steel.
Trump during his first term imposed tariffs of 25 per cent on steel and 10 per cent on aluminium, but later granted several trading partners duty-free exemptions.
Former President Joe Biden later negotiated duty-free quota arrangements with Britain, the European Union and Japan. It was not immediately clear from Trump's announcement what will happen to those exemptions and quota arrangements.
"Quebec exports 2.9 million tons of aluminium to (the US), that is, 60 per cent of their needs. Do they prefer to get supplies from China?" Francois Legault, premier of Quebec, said on X.
"All this shows that we must begin to renegotiate our free trade agreement with the United States as soon as possible and not wait for the review planned for 2026. We must put an end to this uncertainty."
Trump said he would hold a news conference on Tuesday or Wednesday to provide detailed information on the reciprocal tariff plan, adding that he first revealed on Friday that he was planning reciprocal tariffs to ensure "that we're treated evenly with other countries".
with reuters
