Donald Trump has announced steep tariffs on imports of steel and aluminium into the US to address what he says is an "assault on our country."
The president said a 25% tax will apply to steel imports, and 10% will be added to aluminium brought into the US.
Mr Trump said the excess of imported steel and aluminium was a "travesty" and hurts American workers and industry.
Making the long-awaited announcement on Thursday, the president said the industry had been "ravaged by aggressive foreign trade practices".
"It's really an assault on our country," he said.
Sources outside the White House said the tariffs will take effect in 15 days, with Canada and Mexico indefinitely excluded from the duties.
Those briefed on the plans say all countries affected by the tariffs are being invited to negotiate for exemptions, if they can address the threat their exports pose to the US.
The decline of American steel and aluminum production has resulted in extensive job losses for hardworking Americans in industries critical to our national security and economic well-being. More: https://t.co/cJpAq6soNd pic.twitter.com/UzXGbdhi3t— The White House (@WhiteHouse) March 8, 2018