Iran’s foreign minister on Monday vowed vengeance against Israel for an explosion a day earlier at the Natanz nuclear site that he blamed directly on Tehran’s arch enemy.
“The Zionists want to take revenge because of our progress in the way to lift sanctions ... they have publicly said that they will not allow this. But we will take our revenge from the Zionists,” Foreign Minister Mohammad Javad Zarif was quoted as saying by state TV.
Israel has all but claimed responsibility for the apparent sabotage operation that damaged the electricity grid at the Natanz site on Sunday, with multiple Israeli outlets reporting that Mossad carried out the operation, which is believed to have shut down entire sections of the facility.
The sabotage could set back uranium enrichment at the facility by at least nine months, US officials briefed on the operation told the New York Times.
Watch: Iran blames Israel for nuclear site sabotage and vows revenge
Iran on Monday said the person who caused the power outage at one of the production halls at Natanz had been identified.
"Necessary measures are being taken to arrest this person," the semi-official Nournews website reported, without giving further details.
Iran's foreign ministry also said on Monday it is suspending cooperation with the European Union in various fields following the bloc's decision to blacklist several Iranian security officials over a 2019 protest crackdown.
Foreign ministry spokesman Saeed Khatibzadeh "strongly condemned" the sanctions and said Iran is "suspending all human rights talks and cooperation resulting from these talks with the EU, especially in (the fields of) terrorism, drugs and refugees".
The European Union on Monday imposed sanctions on eight Iranian militia commanders and police chiefs, including the head of the elite Revolutionary Guards, over a deadly crackdown in November 2019.
The explosion – which came as US Defence Secretary Lloyd Austin was visiting Israel – could complicate ongoing efforts by Iran and the United States to restore the 2015 nuclear deal, an agreement Tehran signed with major powers in the face of fierce Israeli opposition.
Jen Psaki, US President Joe Biden's spokesperson, denied the US had any involvement in the blast.
Israeli Prime Minister Benjamin Netanyahu – fighting for his political survival at home – last week vowed that he would not be bound to any agreement that would enable Iran to develop "weapons that threaten our extinction".
"Iran has never given up its quest for nuclear weapons and the missiles to deliver them," he told reporters on Monday. "I will never allow Iran to obtain the nuclear capability to carry out its genocidal goal of eliminating Israel."
The Israeli leader made no comment about Iran's accusation that Israel had sabotaged its key Natanz nuclear site.
The explosion at the largely underground facility came the day after Iran’s National Nuclear Day, when it inaugurated new advanced centrifuges, another breach of the nuclear deal that Iran has progressively stepped back from since former US president Donald Trump abandoned three years ago.
On Saturday President Hassan Rouhani hailed the new centrifuges but reiterated Iran’s claims that Iran’s nuclear programme is not aimed at atomic weapons.
Iranian authorities described the incident at Natanz, which has previously been targeted by sabotage attacks, as an act of “nuclear terrorism”.
Iranian Foreign ministry spokesman Saeed Khatibzadeh suggested Israel carried out the attack in an attempt to scuttle talks underway in Vienna aimed at salvaging the nuclear agreement
"Of course the Zionist regime, with this action, tried to take revenge on the people of Iran for their patience and wise attitude regarding the lifting of sanctions," he said.
Iran says that the first step to restoring the agreement is for the United States to lift the crippling economic sanctions it reimposed after withdrawing the agreement.
The US says Iran must first return to compliance. Delegations from Washington and Tehran are not meeting directly at talks in Vienna and an agreement is not expectedly imminently.
Despite this, Israel is concerned at the possibility of a return to an agreement it believes could allow Iran to eventually produce an atomic bomb and Mr Netanyahu has promised to do everything in his power to block a return to the deal.
The US defence secretary – who travelled to Israel on Sunday partly to reassure concerned officials – declined to say whether the Natanz incident is likely to hinder efforts to re-engage with Iran on its nuclear programme.
"Those efforts will continue," Mr Austin said.
Mr Zarif also vowed that talks would go ahead. “If they think our hand in the negotiations has been weakened, in fact this despicable act will make our position in negotiations stronger,” he said.
Watch: Iran and Israel trade barbs after nuclear site sabotage
Analysis by Campbell MacDiarmid
The Natanz incident was the second apparent attack on Iranian interests since indirect talks over the nuclear deal started last week. Analysts suggested that while the timing was not coincidental, these operations were less about derailing the talks and more about showing that Israel was willing to act independently to advance its interests.
Last Tuesday, an Iranian-flagged ship was damaged by an explosion in the Red Sea. Limpet mines reportedly caused the blast on the Saviz, an ostensibly civilian vessel anchored off the coast of Djibouti and believed to be used by Iranian republican guards.
While Israel does not often confirm its covert attacks, US officials told The New York Times that Israel had forewarned Washington of the attack.
“These incidents were timed and tied to the nuclear deal talks and Iran’s nuclear day events but that’s just tradecraft from the Israelis,” said Joel Gulhane, Middle East and North Africa analyst at The Risk Advisory Group.
Such actions would “probably not” scupper the indirect talks between Iran and the United States but showed Israel was willing to act unilaterally, he said.
“As Netanyahu said, Israel’s strategic aims with regards to Iran’s nuclear programme are not bound by the nuclear deal,” he said. “Israel is demonstrating what it can do to Iran's nuclear programme if it needs to.”
Israel maintains that the Joint Comprehensive Plan of Action, as the nuclear deal is formally known, would have enabled a nuclear-armed Iran within 15 years.
“We have to remember that seven years have already passed,” said Amir Avivi, a retired Israeli Brigadier General, who founded a group of 2,000 retired military officers called Habithonistim to advocate for Israel’s security.
“We truly believe it’s an existential threat, the Iranians want to annihilate us, and we take this very seriously,” he said.
Despite attempted reassurances from Washington, Israel fears the new administration of President Joe Biden will not be as amenable as that of Mr Trump.
“The Biden administration is talking to us but it seems like they’re anxious just to go back to this former agreement and quickly lift sanctions. This is very troubling for us,” Mr Avivi said.
That leaves Israel looking for other ways to advance its interest, he said. “The administration has to understand, if they push us back to the wall, we won’t stay silent, we’ll do what’s right for Israel.”