Iranian President Hassan Rouhani has launched a personal attack on Mike Pompeo after the Secretary of State promised the US would be imposing "the strongest sanctions in history" on his country.
Rouhani questioned Pompeo's credibility as a former CIA chief to make decisions for Iran and the world.
The condemnation was swiftly followed by that of Iranian Foreign Minister Javad Zarif who said in a tweet the US was "regressing to old habits" and was a prisoner of its "failed policies."
On Monday Pompeo had also cautioned European firms against continuing to do business in Tehran, toughening up Washington's policy line after its withdrawal from the nuclear pact.
It's a stance highly criticised by EU foreign policy chief Federica Mogherini who said there was "no alternative" to the agreement.
Despite the EU wanting to stick by the deal European firms now find themselves forced to choose between investing there or trading with the US.