America has dismissed the European Union’s attempt to minimise the impact of its Iran sanctions as the first phase of penalties kicked in three months after Donald Trump's withdrawal from the nuclear deal.

A senior US administration official said a move by Brussels, with the support of Britain, to impose a “blocking statute” protecting European businesses trading with Iran was “not something that we’re particularly concerned by”.

The comment came just hours after Jeremy Hunt, the Foreign Secretary, issued a joint statement with the foreign ministers of Germany, France and the EU expressing “deep regret” at America’s decision to reimpose sanctions.

US officials also took a combative stance on countries like China and India – two major importers of Iranian oil – as they said the target would be “zero” oil being sold by Iran and would enforce their sanctions regime “aggressively”.

Mr Trump said in a statement: "We urge all nations to take such steps to make clear that the Iranian regime faces a choice: either change its threatening, destabilising behavior and reintegrate with the global economy, or continue down a path of economic isolation."