Iran says it will enrich uranium to highest level ever after apparent Israeli attack on key nuclear facility

• Iran says it's going to enrich uranium to 60% purity, much closer to weapons-grade levels (90%).
• This could complicate efforts to revive the 2015 nuclear deal.
• This announcement came after an apparent Israeli attack on an important Iranian nuclear facility.

Iran on Tuesday said it will enrich uranium to 60% purity, the highest level its nuclear program has ever seen, following an attack at its Natanz nuclear complex on Sunday that the Iranian government blamed on Israel, the Associated Press reported.

Up to this point, Iran has not enriched uranium higher than 20%. Enriching uranium to 60% purity would push Iran much closer to weapons-grade levels, which is 90%, and well beyond the 3.67% limitation on uranium enrichment set by the 2015 nuclear deal.

Tuesday's announcement came as Iranian and American officials were set to continue indirect talks in Vienna on reviving the 2015 deal, formally known as the Joint Comprehensive Plan of Action (JCPOA). President Joe Biden has made restoring the JCPOA a top foreign policy priority, and the Vienna talks mark the most significant step toward achieving this goal since his inauguration. But Sunday's attack, which damaged Iran's centrifuges, and the subsequent move to ramp up uranium enrichment could complicate the talks.

Deputy Foreign Minister Abbas Araghchi in Vienna on Tuesday said that 1,000 centrifuges will be added to Natanz in addition to moving toward 60% enrichment.

"The damaged centrifuges in Natanz ... would be replaced with more-advanced centrifuges and more-capable centrifuges," he said, per AP. "We insist on what we have asked. All sanctions should be lifted, we verify and then we go back to full compliance if we are satisfied with the verification process."

Iran has demanded the US lift all sanctions for it to return to compliance with the JCPOA. Meanwhile, the Biden administration has maintained there will be no sanctions relief until Iran complies with the deal again, though the State Department said last week that the US is willing to lift sanctions "inconsistent" with the accord.

The Vienna talks, which began last week, showed relative signs of progress heading into the weekend. But Iran's top diplomat, Javad Zarif, in tweets suggested that Sunday's attack at Natanz would give Iran more leverage in the talks. Zarif said the attack, which he described as "nuclear terrorism," was a "foolish gamble." Iran has vowed revenge on Israel.

That said, intelligence officials briefed on the attack told The New York Times that it dealt a major blow to Iran's ability to enrich uranium and could cause a monthslong delay before production is restored at Natanz. Israel has not claimed responsibility, but is widely believed to have carried out the attack. And much like the assassination of a top Iranian nuclear scientist in November, experts say the incident was part of Israel's broader effort to undermine the move to revive the JCPOA.

"It looks like Israel is really trying to send a pretty clear message that not only are they unsatisfied with the way things are going from a diplomatic point of view, but also that they are willing to take steps covertly to try to make diplomacy more difficult," Henry Rome, a senior analyst at Eurasia Group, told PBS.

The 2015 nuclear deal was designed to prevent Iran from developing a nuclear weapon in exchange for relief from economic sanctions. In May 2018, then-President Donald Trump withdrew the US from the Obama-era pact, raising tensions with Iran and setting off a series of events that raised fears of a new war in the Middle East. Israel, which views Iran as a threat, has consistently been a vocal opponent of the JCPOA and any efforts to restore the pact.

Sunday's attack was not the first act of sabotage at Natanz, and the US said it had no involvement.