As Iran and world powers seem to move closer than ever to signing a nuclear agreement, Iran has begun enriching uranium on the second of three cascades, or clusters, of advanced IR-6 centrifuges recently installed at an underground plant at Natanz, according to a report by the UN nuclear watchdog seen by Reuters.
Like the first of those three cascades of up to 174 machines each, the second is enriching uranium to up to 5 per cent fissile purity and the third has not been fed with nuclear material, the confidential report to member states said.
A separate report on Monday said the first cascade had been brought on-stream.
Meanwhile, the EU's foreign policy chief voiced hope on Wednesday about reviving the Iran nuclear deal within days as Israel's leader, a strong opponent, made his case with US President Joe Biden.
The Biden administration is eager to restore the deal trashed by former president Donald Trump and says that Iran has backed down on some demands that held up diplomacy for a year and a half.
“I am hoping that in the coming days we are not going to lose this momentum and we can close the deal,” top EU diplomat Josep Borrell said, after an informal meeting of the bloc's foreign ministers in Prague.
“It's clear that there is a common ground, that we have an agreement that takes into account, I think, everyone's concerns,” he said.
In Washington, National Security Council spokesman John Kirby said the US was also “cautiously optimistic,” but declined to cite a time frame.
“We do believe we're closer now than we have been in certain recent weeks and months due in large part to Iran being willing to drop some of their demands that were not related to the deal at all,” Mr Kirby told reporters.
The EU put forward on August 8 what it called a final text to restore the landmark 2015 agreement, under which Iran was promised sanctions relief in return for stringent restrictions on its nuclear work.
Former president Donald Trump withdrew the US in 2018 and imposed sweeping new sanctions. A return by the Biden administration could put more than one million barrels of Iranian oil back on international markets, bringing new relief as crude prices recede from recent highs.
Iran responded to the EU proposal with proposed changes to which the US replied in turn without divulging the details.
Iran's arch-rival Israel has stepped up pressure on western nations to block the deal and is accused of being involved in a campaign of sabotage and assassinations within Iran to set back the nuclear programme.
Prime Minister Yair Lapid spoke by telephone with Biden after visits to Washington both by Israel's defence minister and national security adviser, with its spy chief due next week.
Mr Lapid and Mr Biden “spoke at length about the negotiations on a nuclear agreement, and the various efforts to stop Iran's progress towards a nuclear weapon”, a statement from the Israeli prime minister's office said.
The two also discussed “Iran's terrorist activity” with Mr Lapid commending Biden for US strikes last week in Syria that Washington said targeted fighters linked to Iran's elite Revolutionary Guards.
The White House did not immediately comment on the call but the Israeli statement said Mr Biden “emphasised his deep commitment to the security of the State of Israel”.
Mr Lapid told journalists last week that the existing agreement “is a bad deal”.
“It would give Iran $100 billion a year” that would be used by Iran-backed militant groups Hamas, Hezbollah and Islamic Jihad, Mr Lapid claimed.
The Biden administration says it is under no illusions about Iran but that Mr Trump's “maximum pressure” approach had achieved nothing other than bringing Tehran closer to building a nuclear bomb.
In one sticking point, Iran has insisted that the UN nuclear watchdog drop a probe of three undeclared sites suspected of sensitive work before the 2015 deal.
“We want to reinforce in the text the idea that the International Atomic Energy Agency concentrates on its technical task and moves away from its political role,” Iranian Foreign Minister Hossein Amir-Abdollahian said on a visit to Moscow.