Over the past year, Iran has made significant advances in its ability to amass enriched uranium, complicating the Biden administration’s effort to revive a 2015 deal aimed at curbing Tehran’s atomic ambitions.
Washington has sought to restart the accord, which was abandoned by President Donald Trump in 2018. After a delay of several weeks, Iran on Wednesday signaled that it would be ready to return to the negotiating table next month after the country’s newly elected president, Ebrahim Raisi, takes office.
American and European officials estimate that Iran could now gather enough fissile material for a nuclear weapon within two to three months.
U.S. officials say that, at least for now, they are confident a return to the terms of the 2015 accord will lengthen that so-called breakout time to around a year—the same as it was in January 2016, when the pact agreed to by the U.S., Iran and five other global powers went into effect.
“There will come a point—but we’re not there yet…where if Iran continues to advance its program and there’s no deal, then it will be very hard, if not impossible, to recapture the nonproliferation benefits” of the original deal, U.S. special Iran envoy Rob Malley told CNN on Wednesday. Mr. Malley said to avoid that, a deal needs to be concluded “in the foreseeable future.”
Assessments of Iran’s potential breakout time vary, depending on assumptions made about the equipment Iran has, its ability to use it and how quickly it can expand its capacity.
Some European officials involved in the talks say they believe Iran’s breakout time, if the pact were revived quickly, could already be less than a year and worry the time cushion could fall further if Tehran continues its nuclear work as talks drag on.
Western officials’ chief worry is that Iran has mastered technology needed to better employ some advanced centrifuges, which it uses to enrich uranium. In particular, Iran has become more effective in using its stock of second-generation so-called IR-2M machines.
Iran had more than a thousand IR-2M machines in 2016, but was barred from using them under the deal. Western diplomats at the time believed Iran’s expertise was too basic for Tehran to deploy them effectively to race to a nuclear weapon. That has now changed, several senior Western diplomats say.
Over the past year, Iran has deployed most of its IR-2M machines—which are three to four times faster than the centrifuges Iran is permitted under the accord to use—and has done so more speedily and successfully than many observers expected.
In addition to limiting the type of centrifuge Iran could use, the 2015 agreement required the removal of two-thirds of Iran’s centrifuges. It also capped the amount of enriched uranium that Iran was allowed to possess at 300 kilograms. The level of permitted enrichment was limited to 3.67%. Weapons-grade uranium is enriched to 90%.
Iran’s breakout time was supposed to remain at one year at least until 2026.
After Mr. Trump pulled the U.S. out of the accord and imposed economic sanctions on Iran, Tehran began moving step-by-step to expand its nuclear activities.
Iran is now producing near-weapons-grade 60% enriched uranium. Last week, the United Nations’ atomic agency reported that Iran had moved forward with plans to produce enriched uranium metal, a material used in the core of a nuclear weapon. Iran says it is producing the metal for peaceful use.
Tehran has also restricted international inspectors’ access to its main Natanz nuclear facility and declined to extend an agreement with the UN’s International Atomic Energy Agency to hand over camera footage and other monitoring material to the IAEA.
Iran says its nuclear work is entirely for peaceful purposes.
Given Iran’s progress on centrifuges, machines which spin uranium into higher purities, European officials have proposed a new three-pronged approach to lengthen Iran’s breakout time. In addition to keeping advanced centrifuges in storage and under seal, they want Iran to rip out the electronic infrastructure it is currently using to run machines banned under the deal and reduce Iran’s capacity for producing new centrifuges at its assembly plants.
Negotiators were close to agreeing that Iran’s uranium stockpile would be sent to Russia. Iran has insisted it won’t allow any of its more advanced centrifuges to be destroyed, say several people involved in talks.
Western diplomats are split into two broad camps on Iran’s strategy for the talks. Some say they believe Tehran wants to restore the 2015 deal but is delaying in the belief that the Biden administration’s eagerness to defuse a potential nuclear crisis could drive Washington to make concessions. Talks, which broke off June 20, may not restart until the second half of August, a senior European official said.
Meanwhile, Iran is using the slow pace of the talks to gain irreversible technical knowledge on uranium metal, centrifuges and production of higher-grade enriched uranium, Western officials say.
Other officials believe there is a real debate in Tehran over whether to return to the deal and, if so, what to seek in return.
Iran’s new president, Mr. Raisi, supported reviving the nuclear deal during his election campaign, but said immediately after that his team would first review in depth the results of the negotiations so far.
Iranian differences of opinion over conditions for returning to the deal have at times flashed into public view. Earlier this week, outgoing President Hassan Rouhani, who spearheaded the 2015 deal, criticized the country’s leadership for not allowing negotiations to be concluded after they resumed in April.
Hard-line politicians and media have long opposed the nuclear deal. The country’s supreme leader, Ayatollah Ali Khamenei, makes the key decisions on strategic issues like the nuclear program.
“They took away the opportunity to reach an agreement from this government,” Mr. Rouhani was quoted saying in Iranian media.
Iran has so far insisted that the U.S. must first drop all Trump-era sanctions, including those on human-rights and terror grounds, offer compensation for that decision and guarantee it won’t exit an agreement again before it would return to the accord.
U.S. and European officials say those demands won’t be accepted.
“We have repeatedly stressed that time is on no one’s side. With its latest steps, Iran is threatening a successful outcome to the Vienna talks despite the progress achieved in six rounds of negotiations to date,” the foreign ministers of France, Britain and Germany said last week.
—Michael R. Gordon in Washington contributed to this article
(This story has been published from a wire agency feed without modifications to the text)