(CNN)Iran nuclear talks resumed Monday in Vienna, Austria, as the US warned Tehran against further uranium enrichment, Israel forcefully lobbied against sanctions relief for Iran and Iran announced its "willingness and seriousness" to reach a deal -- but only if the US lifts sanctions.
The flurry of public messaging was punctuated by a report out of Israel suggesting Iran is preparing to enrich uranium to the level needed to make a nuclear weapon. Two Israeli officials confirmed to CNN the news, first reported by Axios, that Israel had shared intelligence with US officials in recent weeks that suggests Iran is preparing to enrich uranium to 90%.
Those reports follow Iran's own announcement last week about its steady march toward greater stockpiles of enriched uranium, some of it dictated by a law Iran's parliament passed last year that ordered the resumption of uranium enrichment to pressure the US to ease sanctions.
Emerging from the first round of talks about the Joint Comprehensive Plan of Action, as the deal is formally known, the European Union's deputy secretary-general, Enrique Mora, told reporters something has to change, both for the sake of nuclear security and the people of Iran.
'Nothing has changed'
"We have taken stock of the difficult circumstances of the JCPOA," Mora said. "Over the recent months, the Iranian nuclear program has advanced. And at the same time, the United States are imposing the same sanctions. No one, nothing has changed to the previous administration," he noted. "And that situation points in the direction of that we have to bring JCPOA back to life -- both for nuclear commitments and for the benefit of the Iranian population."
Iran's Foreign Ministry spokesperson Saeed Khatibzadeh said Tehran is willing to get on the right track to reach an agreement "if the other side shows the same willingness."
"The government has shown its willingness and seriousness by sending a quality team known to all," Khatibzadeh told a news conference in Tehran. "If the other side shows the same willingness, we will be on the right track to reach an agreement."
The two Israeli officials told CNN that Israel had shared information about Iran's activities with the US in the weeks leading up to Monday's resumption of talks, which had stalled after six rounds of negotiations for almost six months.
The European Union, France, Germany, China and Russia are meeting directly with the Iranians, without the US in the room. US diplomats are participating indirectly, meeting with allies afterward to learn what was discussed and weigh in with their positions. It's not clear if the new Israeli report will complicate matters.
Israeli intelligence suggests that Iran is taking technical steps that would allow it to enrich uranium to 90% purity. Iran has been openly pursuing efforts to increase its stockpiles of enriched uranium.
In an apparent effort to gain leverage in Vienna, Iran announced on Friday that it had grown its stockpile of 20% enriched uranium, just days after announcing that its stock of 60% enriched uranium has grown to 66 pounds (30 kilograms).
According to the Arms Control Association, enriching uranium to 20% "constitutes about 90 percent of the necessary work to enrich to weapons-grade."
Iran's uranium enrichment was limited under the nuclear deal, which then-President Donald Trump pulled the US from in May 2018. Now, as Iran's stockpiles grow, the Arms Control Association says that Iran's breakout time -- the time it would take to produce enough enriched uranium for one bomb -- decreases.
The association estimates that Iran's current breakout time is likely about a month, down from 12 months when the nuclear deal was fully implemented. But it's not clear Iran has the other infrastructure needed to build a bomb, and Iran has also consistently said it is not aiming to build a nuclear weapon.
'Provocative act'
State Department principal deputy spokesperson Jalina Porter would not comment directly on the reports but said Monday that enrichment to 90% purity would be a "provocative act."
"We've made clear that Iran's continued nuclear escalations are unconstructive," she said during a briefing call with reporters. "They're also inconsistent work with what's stated in the goal of returning to a mutual compliance with the JCPOA."
"They won't provide Iran any negotiating leverage as we return to the talks," Porter said.
The White House declined to comment on the matter.
"We will not comment on intelligence matters. But it's no secret that the former administration's decision to abandon the JCPOA led to a dramatic and unprecedented acceleration of Iran's nuclear program. This includes advanced enrichment activities, as recently confirmed again" by the International Atomic Energy Agency, said a senior administration official.
Sending an administration official to Vienna this week, the Biden administration followed through on its pledge to continue engaging in diplomacy as an effort to salvage the Iran deal. Leading into the talks, the US also said it is "prepared to use other options" if the negotiations fail.
'Nuclear blackmail'
Meanwhile, as the nuclear talks resumed with Iran, Israel targeted its diplomatic firepower at the prospect of a possible interim agreement with Tehran that would see sanctions lifted in exchange for a partial freeze on Iran's nuclear program.
Prime Minister Naftali Bennett, in a video message delivered in English, said the United States and its partners must not give in to what he called "Iran's nuclear blackmail."
"Despite Iran's violations and undermining of the nuclear inspections, Iran will be arriving at the negotiation table in Vienna, and there are those who think they deserve to have their sanctions removed and hundreds of billions of dollars poured right into their rotten regime. They're wrong," he said. "Iran deserves no rewards, no bargain deals and no sanctions relief in return for their brutality."
Foreign Minister Yair Lapid, on a whistle-stop visit to Britain and France, two countries participating in the Vienna talks, echoed that message in London.
The day before the talks began, Iran's deputy foreign minister and top negotiator, Ali Bagheri Kani, laid out Iran's message in a Financial Times op-ed. Their first goal: "to gain a full, guaranteed and verifiable removal of the sanctions that have been imposed on the Iranian people. Without this," Bagheri said, "the process will continue indefinitely."
