New EU tariffs on US goods come into force from today.

It comes after President Trump imposed duties on European steel and aluminium products.

Europe is putting a 25% import tax on products including Harley Davidson motorbikes, Levi jeans, bourbon whiskey and orange juice.

The budding trade war has already rattled global markets - but EU policy chief Federica Mogherini said the bloc was left with no choice but to act.

“Clearly the European Union has to protect its interests,” she said.

“This is why – as announced by the president yesterday – the EU will today proceed with the WTO (World Trade Organisation) dispute settlement case and impose additional duties on a number of imports from the United States.”

European Commission president Jean-Claude Juncker has warned that President Trump’s tariffs go against "all logic and history."

"Our response must be clear but measured,” he said. “We will do what we have to do to rebalance and safeguard."

The duties come into force today and will affect €2.8bn worth of US goods.

Markets Editor with the Sunday Business Post, Ian Guider, says there are political reasons for the choice of products.

“If you are looking at putting them on orange juice, where does a lot of orange juice come from in America?

“Florida – one of the key states in American political battles.

“So with the mid-term elections coming up the EU is targeting specific politicians in America, telling them to rein President Trump in.”

President Trump has also heightened trade tensions with China, Mexico and Canada – raising the prospect of a global trade war.