US President Joe Biden on Friday criticized the move by his predecessor Donald Trump to withdraw from the 2015 nuclear deal between Iran and world powers.
“We should’ve never gotten out of in my view,” Biden told reporters in Washington during a joint news conference with Japanese Prime Minister Yoshihide Suga.
Three years ago, Trump trashed the agreement – under which Iran was promised sanctions relief in return for curbs on its nuclear program – and instead imposed sweeping economic sanctions.
Iran and the remaining parties to the deal – France, Britain, Germany, Russia and China — have held talks in Vienna to try to rescue the 2015 nuclear deal and work out a US return to the accord, known as the JCPOA.
Biden reiterated that he supported the 2015 agreement negotiated when he was vice president but would not make "major concessions" to rejoin it, according to AFP.
Iran wants the United States to lift sanctions before it rolls back the measures it took out of compliance in protest a year after the US pullout.
Biden said the US does "not think that it's at all helpful" that Iran this week ramped up uranium enrichment, a move taken in response to sabotage on its Natanz nuclear facility which Tehran blamed on Tel Aviv.
Iran had in recent months already raised enrichment to 20% purity. The JCPOA capped the level of purity at 3.67%, Reuters wrote.
"We are producing about nine grams of 60% enriched uranium an hour," Ali Akbar Salehi, the head of the Atomic Energy Organization of Iran, said.
"But we have to work on arrangements ... to drop it to five grams per hour. But then we will simultaneously produce 20% (uranium)," Salehi said.
Biden, however, said the US is “pleased that Iran has continued to agree to engage in discussions" after booting its nuclear enrichment.
He added it was too early to know whether the Vienna talks would succeed in reviving the nuclear accord.
"I think it's premature to make a judgment as to what the outcome will be, but I think we're still talking," Biden said.
The US has a delegation in the Austrian capital, though there has been no talks between Washington and Tehran in Vienna.
The State Department said Friday that the US delegation would remain in Vienna.
The talks will carry on for several days before breaking so that Iranian and US officials can return home for consultations, a European Union official said on Friday.
"We have this (Iranian) decision to go for 60% enrichment. Obviously this is not making the negotiation easier," the EU official told reporters, calling what happened at Natanz "deliberate sabotage".
Iran said on Tuesday that Iran would activate 1,000 advanced centrifuge machines at Natanz.
Multiple Israeli media outlets have quoted unnamed intelligence sources as saying the Mossad spy service carried out the sabotage operation at the Natanz complex. Israel – widely believed to be the only Middle Eastern country with a nuclear arsenal – has not formally commented on the incident.