Trump finally announced Thursday that he would impose a 25 percent tariff on steel imports and a 10 percent tariff on aluminum imports.
Those two countries were excluded due to "shared" commitments on national security and the reduction of excess production of steel worldwide, a provision aimed mainly at state-backed Chinese companies that Trump blames for having flooded the world with cheap steel.
Railroad tracks run past the blast furnaces of the now-closed Bethlehem Steel mill in Bethlehem, Pennsylvania, April 21, 2016.
In a tone of blackmailing, Trump also said Canada will be exempted only if a new North American Free Trade Agreement (NAFTA), which the US President alleged to have incurred loss to his country, is signed.
Trump said the tariffs - which will come into effect after 15 days - will not initially apply to Canada and Mexico, and that close partners on security and trade could negotiate exemptions.
The US president lauded a special relationship with Australia while admonishing another key ally, Germany, during remarks in Washington on Thursday.More news: Richard Sherman To Meet With 49ers On Saturday
Trump has complained about low-priced Chinese exports of steel and aluminum, but the latest move was likely to hit Japan and South Korea harder.
Sen. Cory Gardner, R-Yuma, said he agreed with Trump's view that the USA needs fair trade agreements, but he thinks Trump's broad tariffs could misfire instead of deliver higher wages and economic growth.
European Commission Vice-President Jyrki Katainen said: "We all have to choose whether we want rules-based trade - which supports rules-based world order - or do we want rule of force, or the rule of the strongest, which we have now seen?"
They wrote that adding taxes in the form of tariffs would undermine the economic momentum of the recently passed GOP tax plan. The former real estate developer said politicians for years lamented the decline in the industries, but nobody was willing to take action.
European industry associations called on Malmstrom to respond if the EU was subjected to the tariffs, saying they would hit the steel and aluminium sectors hard.
"If you really think there's going to be mass layoffs in the automotive industry over one half of 1 percent", he said, "you're wrong".
On Thursday, Trump had said that America will remain open to modifying or removing the tariffs for individual nations. At the same time, the number of workers in the steel industry has fallen off, so the real decline in the United States steel industry employment may be from technology and productivity gains, rather than foreign steel.