The US and Iran appear to have edged closer to an agreement that would see a revival of the 2015 nuclear deal.

Indirect talks in Vienna last week—in which European diplomats shuttled between the Iranian and US delegations in an attempt to bridge differences over how to restore the accord, also known as the JCPOA, which is meant to shield Tehran from major sanctions in return for Iranian compliance with measures designed to keep its nuclear development programme entirely civilian—were described by the Biden administration as “constructive”, while the Islamic Republic indicated that it was ready to debate the details of a possible agreement.

Jake Sullivan, United States National Security Adviser, told Fox News on April 18 that “the talks in Vienna have been constructive in the sense that there is real effort under way there”. World powers were focused on restoring the agreement, abandoned by former US president Donald Trump in May 2018, on a “compliance for compliance” basis.

Iran’s lead negotiator, Deputy Foreign Minister Abbas Araghchi, said on April 17 that a “new understanding” was taking shape at the talks. Iran would begin work on a full draft text for negotiators to discuss, he added.

Separately, Iran has changed its description of how its biggest uranium enrichment facility, at Natanz, came to be severely damaged in an attack last week. Tehran previously described the attack, which it blames on Israel, as a cyber-attack, but officials quoted by Iranian state TV at the weekend talked of a limited explosion that hit a small part of the electricity-feeding path to the centrifuges’ hall and said it was explosive materials and not a cyber-attack that caused the blast.

State TV also reported officials as naming a man that intelligence authorities allege was responsible for the attack at Natanz. Reza Karimi fled Iran shortly before the blast, Network One said, showing a man's photo on what it said was an Interpol wanted poster.

The Financial Times, meanwhile, reported on April 18 that senior officials from Saudi Arabia and Iran have been holding talks to repair relations. It cited three unidentified officials. The meeting in Baghdad on April 9 reportedly included discussions about recent attacks and would be followed by another round of talks this coming week, it said.