European and Canadian leaders have reacted to Donald Trump’s decision to impose tariffs on steel and aluminium producers.

The Trump administration has gone ahead with threatened tariffs on steel and aluminium as Europe and Canada pledge to hit back.

The president of the European commission, Jean-Claude Juncker, promised immediate retaliation after the US commerce secretary, Wilbur Ross, said EU companies would face a 25% duty on steel and a 10% duty on aluminium from midnight on Thursday.

Europe, along with Canada and Mexico, had been given a temporary reprieve from the tariffs after they were unveiled by Donald Trump two months ago.

However, Wilbur Ross sent shudders through global financial markets when he said insufficient progress had been made in talks with three of the US’s traditional allies to reduce America’s trade deficit and that the waiver was being lifted.

The move from Washington – which comes at a time when Trump is also threatening protectionist action against China – triggered an immediate and angry response from Canada, Brussels and various  European capitals.

Jean-Claude Juncker called the US move “unjustified” and said the EU had no choice but to hit back with tariffs on US goods and a case at the World Trade Organisation in Geneva.

Juncker added:  "We will defend the Union’s interests, in full compliance with international trade law."

The UK, which has hopes of agreeing a trade liberalisation deal with the US after Brexit, expressed alarm at US commerce secretary, Wilbur Ross’s announcement.

Liam Fox, the international trade secretary, said Britain would not rule out countermeasures or taking Washington to the WTO, which arbitrates on global trade disputes.

Speaking to Sky News, Fox attacked the tariffs as “patently absurd” and urged the US to think again. “It would be a great pity if we ended up in a tit-for-tat trade dispute with our closest allies.”