JERUSALEM — The last time that the centrifuges crashed at Iran’s underground nuclear fuel-production center at Natanz, more than a decade ago, the sabotage was the result of a joint Israeli-American cyberattack intended to slow Tehran’s progress toward nuclear weapons and force a diplomatic discussion.

When they crashed again this weekend, the White House claimed that the United States had no involvement.

The performance raised the question of whether Israel was acting on its own to strike Iran and undermine American diplomacy since the Biden administration seeks to reconstitute a nuclear arrangement. Or, alternatively, whether Israel was operating in concert with American interests, carrying out the dirty work that would weaken Irans negotiating position in the talks.

The White House was saying virtually nothing in public on Monday about the apparent explosion inside Iran’s Natanz facility, under more than 20 feet of reinforced concrete, which destroyed the power supply that keeps the centrifuges spinning at supersonic speeds, enriching uranium.

“The U.S. was not involved in any manner,” the White House spokeswoman, Jen Psaki, said Monday. “We don’t have anything to add on speculation about the causes or the impacts. ”

White House officials didn’t comment on whether the United States had been given advance notice of the attack.

Defense Secretary Lloyd J. Austin III, who landed in Israel on Sunday, the morning after the attack happened, held two press briefings before he left Israel on Monday and never once uttered the word Iran.

White House and State Department officials said they had no idea whether the Iranians would appear in Vienna again on Wednesday, when the talks were scheduled to resume.

In Tehran, lawmakers asked Foreign Minister Mohammad Javad Zarif to suspend the talks, saying that Iran shouldn’t be engaged in negotiations when it’s under attack.

Talks under pressure have no significance, said Abbas Moghtadaie, the deputy chairman of Parliaments national security and foreign policy committee, said in a Clubhouse discussion on Monday. “This was a message we conveyed very clearly today. ”

The Biden administration is seeking to revive an arrangement, scuttled by President Donald J. Trump three decades ago, where Iran accepted limits on its nuclear program in exchange for the lifting of sanctions. Israel’s prime minister, Benjamin Netanyahu, opposed the initial agreement, and it has made no secret of his opposition to resurrecting it.

Mr. Zarif, in a statement broadcast by Iranian state television, said that Israel wanted “to take revenge because of our progress in the way to lift sanctions. ”

But we will take our revenge on the Zionists, he continued.

His comments highlighted the risk of escalation in a yearslong shadow war between Iran and Israel, one which is occurring in the deserts of Natanz, along the shipping routes of the Persian Gulf and in the leafy suburbs of Tehran, where Mohsen Fakhrizadeh, the leader of what American intelligence officials say was Iran’s secret nuclear weapons program, was killed in December by a remote-controlled gun as he drove to his weekend home.

For the Iranians, the attack this weekend was another humiliating indication that its program was penetrated by spies and saboteurs, who have carried out a series of brazen attacks. While Israel usually stays silent when strikes like this occur, Israeli news outlets, citing intelligence sources, attributed this one to the Mossad, the Israeli spy agency.

An intelligence official who asked not to be identified in order to discuss covert operations stated an explosive device had been smuggled into the Natanz plant, was detonated remotely, and took out both the primary and backup electrical systems.

The head of the Iranian Parliament’s energy committee, Fereydoun Abbasi, appeared to confirm that account in an interview with state television on Monday.

The enemys plot was very lovely, ” he said. “I’m looking at it from a scientific point of view. They thought about this and used their experts and planned the explosion so both the central power and the emergency power cable would be damaged. ”

A spokesman for the Atomic Energy Organization of Iran, Behrouz Kamalvandi, said Monday the explosion had exposed a hole so large that he fell into it, injuring his head back, leg and arm.

Just how much damage was done is unclear.

Intelligence officials indicated that it would require several months for Iran to undo the damage.

Ali Akbar Salehi, the head of Iran’s Atomic Energy Organization, said emergency electricity had been restored at Natanz on Monday and enrichment had not stopped at the centre. But it might be running at a fraction of the amount it was before.

A large portion of the enemys sabotage can be restored, and this train cannot be stopped, ” he told the Iranian news media on Monday.

But the attack, the newest in a series of major security breaches in the past year, has led to finger-pointing in Tehran and accusations of infiltration at the highest ranks of Iran’s security devices. The intelligence unit of the Islamic Revolutionary Guards Corps is responsible for both procuring nuclear websites and protecting nuclear scientists.

Mr. Moghtdaie said his committee would investigate what he called “very clear security infiltrations. ”

Vice President Eshaq Jahangiri said the thing responsible for protecting Natanz against attacks must be held accountable. The attacks, he said, could produce “ catastrophic consequences” for Iran’s reputation, security and economy.

And on Social Networking, conservative commentators called for an overhaul in the leadership of the Atomic Agency and for the Supreme National Security Council to take over the nuclear file from the Foreign Ministry.

The Natanz incident is either treason with infiltration or without, tweeted one commentator, Seyed Peyman Taheri. “The cracks of your incompetence are being filled. Fix the holes. ”

Some American officials, declining to speak on the record, expressed concern on Monday that the attack would induce the nuclear program more deeply underground, where it’d be tough to reach. Iran already headed in that direction years ago, when it built a small plant deep inside a mountain near the city of Qum.

It was not the first time Iran’s adversaries had seemed at disrupting power supplies to undercut the country ’s military or nuclear programs. A similar technique was studied more than a decade ago by American officials but abandoned in favor of inserting malware, known as Stuxnet, as a more exact way to knock the centrifuges out of equilibrium and ruin them.

The USA also had a whole battle plan for dealing with Iran that included attacks on its power grids. It was never implemented, but elements of the plan to live on today.

More immediately, the leaking of details about Israeli involvement raised fears that Iran would want to save face by mounting a stronger military response than usual.

After Israeli officials are quoted, it requires the Iranians to take revenge, Danny Yatom, a former head of the Mossad, said in an interview Monday with a radio station run by the Israeli Army.

There are actions that must remain in the dark, ” he said.

Stephen Slick, who once managed the American intelligence agencies’ dealings with the Mossad, noted on Monday that the Israelis would have had several motives to attack.

The varied policy messages likely include a pointed reminder to the U.S. and E.U. to not overlook Israels interests and freedom of action, said Mr. Slick, now the manager of the intelligence studies project at the University of Texas at Austin. “Iran was reminded of its own persistent vulnerability to Israeli military and intelligence activities. ”

In Israel, some also questioned whether the attack had served a domestic purpose for Mr. Netanyahu, instead of just a foreign policy objective.

Mr. Netanyahu is standing trial for corruption and is struggling to form a new coalition government after a general election that gave no party an overall majority. Some analysts said they believed that a very public confrontation with Iran might help Mr. Netanyahu persuade wavering coalition partners that currently isn’t the time to eliminate a seasoned prime minister.

He might want to both build up his image and make a small amount of a foreign policy crisis, which then helps him resolve the coalition crisis, Chuck Freilich, a former deputy national security adviser in Israel, said on Monday.

But publicly, the United States and Israel kept up the picture of friendly allies.

In a joint press briefing in Jerusalem, Mr. Austin did not mention Iran at all, while Mr. Netanyahu referred only obliquely to the attack on Sunday.

At a separate briefing with Defense Minister Benny Gantz, when an Israeli reporter asked Mr. Austin concerning the explosion, Mr. Gantz cut him off.

Iran has maintained that its nuclear program is peaceful and aimed at energy development. However, Israel sees it as an existential threat, since Iranian leaders have often called for Israel’s destruction.

We both agree that Iran must never have nuclear weapons, Mr. Netanyahu said on Monday. “My policy as prime minister of Israel is clear. I will never allow Iran to obtain the nuclear capability to carry out its genocidal objective of eliminating Israel, and Israel will continue to defend itself against Iran’s aggression, and terrorism. ”

In Washington, Ms. Psaki said she anticipated that the discussions with Iran would resume Wednesday as planned.

We expect them to be tough and long, she said. “We have never been given any indication about a change in participation for these discussions. ”

Patrick Kingsley reported from Jerusalem, David E. Sanger from Washington and Farnaz Fassihi from New York. Reporting was contributed by Myra Noveck from Jerusalem, Steven Erlanger from Brussels and Eric Schmitt from Washington.