Tehran has stepped up diplomatic pressure on the Biden administration to re-enter the 2015 nuclear agreement and begin to lift sanctions promptly by proposing Iran will return to full compliance simultaneously by restoring limits on uranium enrichment and stockpiling.
Iran's foreign minister Javad Zarif has suggested EU foreign policy chief Josep Borrell could "synchronise" or "co-ordinate" efforts of the sides to restore the accord under which Iran agreed to curbs on its nuclear activities in exchange for an easing of sanctions.
As head of the commission implementing the deal, Mr Borrell has accepted the challenge, and spoken to the White House. It remains to be seen if EU efforts will bear fruit. If Mr Borrell fails Iran could revert to the après-vous impasse, exacerbating tensions between the US and Iran and in the region.
While Joe Biden, the US president, has said he will return to the deal he has given no deadline. Consequently, secretary of state Antony Blinken has ignored Mr Zarif's proposal and continued to argue Iran must resume compliance before the US recommits and eases sanctions.
He appears to be at odds with Mr Biden's national security adviser Jake Sullivan and Iran envoy Robert Malley, who have called for urgent re-entry before Iran goes to the polls in June to elect a new president to replace Hassan Rouhani, a pro-deal moderate. His successor could be a rejectionist hardliner.
Iran has put political pressure on the US to return to the deal by boosting uranium enrichment from the prescribed 3.67 to 4.5 per cent purity, amassing a stockpile 10 times the amount permitted, deploying banned high-speed centrifuges, and enriching 17kg of uranium to 20 per cent.
Iran has warned it will block UN inspectors from some sites by the end of this month if the US dawdles over re-entry.
The two sides should be able to return to the deal in short order. Mr Zarif has dismissed Mr Blinken’s claim that Iran would take time to return to compliance by saying Tehran could turn off enrichment “in one day”.
Iran can also quickly export excess enriched uranium to Russian warehouse centrifuges, and cease enriching above the limit.
Mr Biden can simply sign an executive order to rejoin and lift sanctions covered by the deal.
Ex-US president Donald Trump withdrew from the deal in 2018 and imposed punitive sanctions while Tehran was in full compliance.
Iran stuck with the deal for a year while urging Britain, France, Germany, Russia and China, the agreement's other signatories, and the EU to defy Trump's "maximum pressure" campaign, which has cut Iranian oil and precious metals exports and blocked Iranian international financial transactions.
Iran’s economy has contracted, its currency has lost value, and Iranians have been deprived of food and medical supplies, causing acute distress since last year. Coronavirus has infected 1.43 million Iranians and killed 58,000.