Donald Trump has declared that “trade wars are good” as he prepared to impose a 25% tariff on steel imports – raising fears of “serious damage” to the industry in the UK.
The US President also plans a 10% tariff on aluminium imports, warning that his country’s metal industries were being “decimated”.
Trade association UK Steel said the proposed measures would be an “extremely blunt” reaction to a complex global problem.
Unite union national officer for steel Tony Brady said if the tariffs applied to the UK, they would be “devastating”.
Brussels has indicated it could retaliate if the tariffs hit EU exports.
Jean-Claude Juncker has said the EU could take action in response to US steel tariffs (Suzanne Plunkett/PA)
European Commission president Jean-Claude Juncker said: “We will not sit idly while our industry is hit with unfair measures that put thousands of European jobs at risk.”
Commission spokesman Alexander Winterstein said the EU would react “swiftly, firmly and proportionately”, adding: “We have been preparing for this situation for a long time and because of these preparations, now we are ready.”
But Mr Trump gave no indication he was prepared to back down, insisting that the US stood to gain from a trade war.
“When a country (USA) is losing many billions of dollars on trade with virtually every country it does business with, trade wars are good, and easy to win,” he said on Twitter.
Downing Street said it remained unclear whether Mr Trump’s plans – expected to be set out in detail next week – would apply to the UK.
A Downing Street spokesman added: “We are engaging with the US on what this announcement means in practice.
“We are particularly concerned by any measures which would impact the UK steel and aluminium industries.
“Over-capacity remains a significant global issue and we believe multi-lateral action is the only way to resolve it in all parties’ interests.”
The issue is particularly sensitive given the UK’s hopes of striking a post-Brexit trade deal with Mr Trump’s USA.
UK Steel’s head of policy, Richard Warren, said around 15% of the industry’s exports were to the US, amounting to £360 million of high-value products.
“These measures would seriously undermine our ability to compete in this market,” he said.
“Equally there is significant apprehension about the indirect impacts of these measures in the form of steel trade diverted away from the US to other markets, such as the UK.
“In short, these measures would cause serious damage to the prospects of many steel producers here.”
He added: “If next week’s official announcement does reveal the worst, there is a strong message here for the UK Government as well.
“In its imagined post-Brexit role as the vanguard for global free trade, it must remember that not everyone is on the same page and not everyone is playing by the same rules.”
Mr Brady said his union’s members had already been hit by the dumping of Chinese steel.
He said: “Any tariffs imposed on UK steel by President Trump on a scale that is being mooted would be misguided and deprive US manufacturers of some of the most specialist steel in the world.
“The dumping of cheap Chinese steel into the UK took our world-class British steel industry to the precipice because of the Government’s inaction.
“Government ministers and Theresa May must back Britain’s steelworkers and manufacturing communities by securing assurances from president Trump that they will not be caught up in a global tariff war between the US and countries such as China.”