The Natanz nuclear facility in Iran mysteriously misplaced energy on Sunday, Iranian officers stated, a blackout that got here throughout negotiations in Vienna geared toward reinvigorating the nuclear cope with Tehran that the Trump administration left.

Energy was minimize throughout the power, Behrouz Kamalvandi, a civilian nuclear program spokesman, advised Iranian state tv, The Related Press reported.

“We nonetheless have no idea the explanation for this electrical energy outage and should look into it additional,” Mr. Kamalvandi stated. “Luckily, there was no casualty or harm, and there’s no specific contamination or downside.”

Malek Shariati Niasar, an Iranian lawmaker who serves as a spokesman for the Parliament’s power committee, wrote on Twitter that the outage was “very suspicious,” A.P. reported. He raised the opportunity of “sabotage and infiltration.”

Suspicion in Iran after such disruptions has usually centered on Israel, which has sabotaged the nuclear program previously and regards Iran as its most potent navy adversary. However neither the Israeli navy nor the Protection Ministry would touch upon the matter on Sunday.

Israel welcomed President Donald J. Trump’s repudiation of the nuclear deal three years in the past, and it has expressed deep concern about President Biden’s intentions to revive it.

The disruption at Natanz comes at a fragile time — barely every week after diplomatic talks in regards to the accord started in Vienna, and sooner or later after Iran began working new centrifuges that enrich uranium.

Whereas there is no such thing as a direct dialogue between Iran and the US on the talks, the opposite contributors within the settlement — Britain, China, France, Germany and Russia, underneath the chairmanship of the European Union — are engaging in a form of shuttle diplomacy.

One working group is specializing in the best way to raise financial sanctions imposed by the Trump administration, whereas one other is taking a look at how Iran can return to the phrases that set limits on enriched uranium and the centrifuges wanted to supply it.

Iran has stated that its nuclear ambitions are peaceable, and that whereas it intends to steadily resume nuclear actions prohibited underneath the deal, it may simply reverse course if the sanctions had been rescinded. On Saturday, President Hassan Rouhani of Iran celebrated the inauguration of Iranian centrifuges that shorten the time wanted to complement uranium, the gasoline for nuclear bombs.

However Mr. Rouhani additionally insisted that Iran’s efforts weren’t supposed to supply weapons.

“If the West seems to be on the morals and beliefs that exist in our nation, they are going to discover that they shouldn’t be frightened and delicate about our nuclear know-how,” Mr. Rouhani stated in remarks reported by Iran’s Mehr News Agency.

Phrase of the Natanz outage got here as Lloyd Austin, the U.S. protection secretary, was in Israel on Sunday for talks with Prime Minister Benjamin Netanyahu and the nation’s protection minister, Benny Gantz.

On the assembly, Mr. Gantz stated, “We’ll work intently with our American allies, to make sure that any new settlement with Iran will safe the important pursuits of the world and the US, forestall a harmful arms race in our area and shield the State of Israel.”