Iran’s atomic chief warned on Tuesday that the Islamic Republic needs only five days to ramp up its uranium enrichment to 20 per cent, a level at which the material could be used for a nuclear weapon.

The comments made by the Head of the Atomic Energy Organisation of Iran, Ali Akbar Salehi, to Iranian state television come as US President Donald Trump has repeatedly threatened to renegotiate or walk away from the 2015 nuclear deal.

Salehi’s warning, along with recent comments by Iranian President Hassan Rouhani, shows that Iran is willing to push back against Trump while still acknowledging they want to keep the deal, which lifted crippling economic sanctions on the country.

“If there is a plan for a reaction and a challenge, we will definitely surprise them,” said Salehi, who also serves as one of Rouhani’s vice presidents.