Five world powers trying to save their 2015 nuclear deal with Iran from U.S. efforts to overturn it are grappling with a new setback as they meet with Iranian officials in Vienna Friday.
A day before Britain, France, Germany, China and Russia were to hold talks with Iran in the Austrian capital, Moscow said it was suspending its work to reconfigure Iran's underground Fordow nuclear facility for civilian medical research. The Trump administration had warned last month that it would revoke a waiver shielding Moscow from U.S. sanctions against the Fordow project starting Dec. 15.
TVEL, a unit of Russian state-owned nuclear energy company Rosatom, had been working on the Fordow project since 2017. The project had been one of several that Iran agreed to undertake with international companies to modify various Iranian nuclear sites in ways that would ensure their peaceful, civilian uses, rather than military ones.
Those projects were part of the 2015 deal in which Iran accepted restrictions on its nuclear activities in return for six world powers giving it relief from international sanctions.
The U.S. withdrew from that agreement last year, saying it did not do enough to prevent Iran from developing nuclear weapons or engaging in other perceived malign activities. Tehran has said its nuclear ambitions are solely peaceful.
TVEL announced the suspension of its Fordow work in a Thursday statement on its website. The goal of the project had been to convert about one-third of the facility's 1,044 early generation IR-1 centrifuges from being programmed to make enriched uranium - a key nuclear weapons ingredient - into being capable of making stable isotopes for medical purposes.
The Rosatom subsidiary attributed its suspension of the project to Iran's Nov. 6 move to resume the use of other IR-1 centrifuges at Fordow to produce low-enriched uranium. TVEL said it was "technically impossible" to produce medical isotopes with some centrifuges while other centrifuges in the same room were enriching uranium and spreading traces of it everywhere.
"To resume this work, we must stop and dismantle the cascades where uranium enrichment takes place and thoroughly clean the premises and equipment," TVEL said.
Iranian officials described the resumption of enrichment at Fordow as their fourth in a series of gradual violations of the nuclear deal, a strategy aimed at pressuring the deal's European and other remaining signatories to do more to compensate Tehran for the impact of U.S. sanctions that President Donald Trump has been re-imposing and intensifying since last year.
Trump has said the escalating sanctions are part of a U.S. campaign of "maximum pressure" on Iran to agree to a new deal curbing its nuclear and other activities opposed by Washington.
As part of the campaign, Secretary of State Mike Pompeo told a Nov. 18 press briefing that Washington will revoke its sanctions waiver for international work at Fordow Dec. 15. That announcement put Russia's Rosatom at risk of being hit with U.S. sanctions if it continued the work after that date.
Pompeo said the U.S. decision was in response to Iran resuming enrichment at the once-secret Fordow site earlier in November. He said there was "no legitimate reason" for Iran to take the step and called for it to be reversed immediately.
Russian Deputy Foreign Minister Sergei Ryabkov, who is representing Moscow at the Vienna meeting of the Joint Commission of nuclear deal parties, cited the prospect of U.S. sanctions on Rosatom as another reason for TVEL's suspension of the Fordow project.
Speaking to Russian media Thursday, Ryabkov said Moscow needed to "analyze ... the potential negative consequences of the American measures," a reference to the impending termination of the sanctions waiver.
A report by Russian newspaper Kommersant quoted Russian atomic energy expert Alexander Uvarov as saying Rosatom has many international projects and did not want to risk hurting them by exposing itself to U.S. sanctions.
Ryabkov said he would use the Vienna talks to raise the issue of the U.S. preparing to sanction international work at Fordow, a move he criticized as an attempt to break up the nuclear deal.
Some analysts predicted Iran and the five world powers in Vienna likely would agree that the U.S. is to blame for the suspension of the Fordow project and avoid blaming each other for the setback to the deal or using its dispute resolution mechanism to resolve the issue.
"The Europeans realize that triggering the dispute resolution process could end in a re-imposition of U.N. Security Council sanctions and that would kill the JCPOA," analyst Kelsey Davenport of the Arms Control Association told VOA Persian, using an acronym for the nuclear deal, formally known as the Joint Comprehensive Plan of Action. "So I think they will be judicious in their decision-making process before going down that road."
But Davenport said Britain, France and Germany could act if Iran follows through on a threat to more seriously breach its nuclear deal commitments in January and moves closer to having the capability to make an atomic bomb.
"The Europeans may no longer see security value in remaining in the deal and trigger that dispute resolution mechanism," she said. "So the window to try to preserve the JCPOA and bring Iran back into compliance is unfortunately closing."
"At the moment, I don't think that is what the Iranians want," said Behnam Ben Taleblu, an analyst at the Foundation for Defense of Democracies, also speaking to VOA Persian.
"The Iranians have an incremental strategy (for violating the nuclear deal) for a reason, which is to keep the JCPOA on life support, in case there is a change in Washington in 2020," Taleblu said. "At that point, they could tempt a new U.S. president to come back into the deal and perhaps provide Tehran with some kind of payment for the damages incurred during sanctions."
Iran did not immediately comment on what it plans to do with its nuclear program following the Russian exit from Fordow.
This article originated in VOA's Persian Service.