The US is taking the wrong approach by seeking tariffs on steel and aluminium imports and it would be "absurd" for Britain to be caught up in them, British Trade Secretary Liam Fox says.
President Donald Trump put import tariffs of 25 per cent on steel and 10 per cent for aluminium but exempted Canada and Mexico and offered the possibility of excluding other allies.
The European Union has said it should be exempt from the tariffs.
Fox said there was overproduction of steel in the world, mainly coming from China, but protectionism "never really works", adding British steel was used to supply the US military.
"So it's doubly absurd that we should then be caught on an investigation on national security," Fox said told the BBC on Thursday.
"We can deal multilaterally with the overproduction of steel but this is the wrong way to go about it."
He said he would raise the issue with the US in a trip to Washington next week.
Fox's comments came after trade body UK Steel said the tariffs could have a "profound and detrimental impact" while the Community union demanded action to protect British jobs and avoid a "global trade war".
Labour MP Stephen Kinnock, whose Welsh constituency includes the giant Port Talbot steelworks, said Theresa May had "let down" British workers by failing to stand up to the US president.