Iran's atomic agency chief yesterday hit out at European powers, saying their broken promises gave the Islamic republic little choice but to scale back its commitments under a nuclear deal.

Ali Akbar Salehi was speaking to reporters alongside Cornel Feruta, the acting head of the International Atomic Energy Agency who was on a one-day visit to Tehran.

The IAEA official's visit comes a day after Iran said it was firing up advanced centrifuges that enrich uranium at a faster rate — the latest blow to the landmark 2015 nuclear deal.

It was the third step in a strategy Iran implemented in May, reducing its nuclear commitments in a bid to force the deal's remaining parties to deliver on promises of relief from crippling US sanctions.

Britain, France and Germany have been trying to save the nuclear deal, which began unravelling last year when US President

Donald Trump withdrew from it and began reimposing the punitive measures against Iran.

"The European Union was supposed to be the replacement of the US but, unfortunately, they failed to act on their promises," Salehi said in comments aired on state television.

"We heard the EU spokesperson say they would be committed to the JCPOA as long as Iran is," he said, referring to the deal by its formal name, the Joint Comprehensive Plan of Action.

“I am wondering. Are they committed to non-adherence? Are they committed to breaking promises? Unfortunately, the Europeans have done this so far."

The head of Iran's Atomic Energy Organisation said the JCPOA was now just a "one-way street".

"The street was supposed to be two-way. If it's going to be one-way, the Islamic Republic of Iran will definitely make the right decisions at the right time like it has done with these three steps," said Salehi.