Mike Pence, the US vice president, has accused Britain, France and Germany of trying to sabotage American sanctions against Iran and called on the European states to withdraw from the 2015 nuclear deal.

In an unusually blunt attack on America’s traditional European allies, Mr Pence told a summit in Warsaw that the three countries were leading “an effort to break American sanctions against Iran’s murderous revolutionary regime”.

He focused his criticism on a financial mechanism created by the three states and the EU to allow European firms to continue trading with Iran in a way that skirts punishing US sanctions.

“It's an ill-advised step that will only strengthen Iran, weaken the EU, and create still more distance between Europe and the United States,” Mr Pence said.

He said the British, French, and German governments had “not been nearly as cooperative” in backing America’s anti-Iran policy as Israel and the Gulf Arab states like Saudi Arabia and the UAE.

Mr Pence said for the first time that the three countries should pull out of the nuclear agreement, which was signed in 2015 by Britain, France, Germany, Russia, China, the US and Iran. “The time has come for our European partners to withdraw from the Iran nuclear deal.”