BRUSSELS — Scrambling to save the nuclear agreement with Iran, European foreign ministers declared Monday that Iranian breaches so far were not serious enough to take steps that could lead to reimposed international sanctions and a collapse of the accord.
That conclusion, at a meeting in Brussels, effectively extended a lifeline for the 2015 nuclear agreement, which has been increasingly imperiled since the United States abandoned the accord more than a year ago and renewed its own sanctions on Iran.
The European Union ministers reiterated their view that the agreement was the only option for curbing Iran’s nuclear program.
In recent weeks Iran has exceeded the amount and purity of the uranium it is permitted under the accord, transgressions confirmed by the International Atomic Energy Agency. The Iranians have said they intend to breach the limits even more unless they get what the accord promised Iran: economic relief.
Triggering the dispute-resolution article in the accord would start a process that could lead to the restoration of all the sanctions placed on Iran. That, many analysts say, would almost certainly would doom the agreement.
The European reluctance to use the provision came despite pressure from both the United States and Israel, which say Iran’s breaches are a signal of the country’s intent to move toward the capacity to make an atomic bomb. Under the accord, Iran has vowed to never seek such a weapon.
“For the time being, none of the parties to the agreement has signaled their intention to invoke this article,” Federica Mogherini, the European Union’s top foreign policy official, told a news conference after the foreign ministers meeting in Brussels.
Ms. Mogherini said that “none of them, for the moment, for the time being, with the current data we have had” believe that there has been “significant noncompliance.”
The conclusion was quickly denounced by Prime Minister Benjamin Netanyahu of Israel, whose government regards Iran as the country’s most serious security threat.
“The European Union’s response to Iranian violations reminds me of the European appeasement of the 1930s,” Mr. Netanyahu said in a statement reported by Israeli news media. “There are probably some in Europe who will not wake up until Iranian missiles fall on European soil. Then it probably will be too late.”
Ms. Mogherini, echoing the view of the meeting’s participants, said that the nuclear deal was still the only available option.
“The deal has avoided Iran developing a nuclear weapon, and today everyone recognizes that there is no alternative,” she said. “This is the most dramatic and difficult stage.”
Jeremy Hunt, Britain’s foreign secretary, said he saw little time left to save the deal.
“Iran is still a good year away from developing a nuclear bomb,” Mr. Hunt said. “There is still some closing, but small window to keep the deal alive.”
The European participants in the deal — Britain, France and Germany — issued a joint statement Sunday evening that said they were still committed to it. They expressed regret that the United States had reimposed sanctions on Iran “even though that country had implemented its commitments under the agreement.”
“We believe that the time has come to act responsibly and to seek ways to stop the escalation of tension and resume dialogue,” the three countries said in the statement.
But the Iranian foreign minister, Mohammad Javad Zarif, said that he saw little reason to be optimistic that the Europeans could save the agreement — known formally as the Joint Comprehensive Plan of Action — by alleviating the punishing effects of American sanctions against Iran.
“The Europeans claim they were willing to maintain the J.C.P.O.A., but we have not seen Europe yet to be ready for an investment,” he said on Sunday after arriving in New York for a meeting of the United Nations, Iran’s state-run Press TV reported.
Mr. Zarif, who was educated in the United States, speaks colloquial English and has extensive contacts in Western media and foreign policy circles, has long vexed the Trump administration, which accuses him of spreading lies. It has considered placing sanctions on Mr. Zarif, a move that would sever an important diplomatic conduit with the United States.
In a sign of the antipathy, administration officials granted Mr. Zarif a restrictive visa that limits him to the United Nations headquarters, the Iranian Mission and the Iranian ambassador’s residence.
“They are worried about Mr. Zarif’s influential work trips and his media interviews, and the impact it will have on American public opinion,” said Seyed Abbas Mousavi, an Iran Foreign Ministry spokesman.
Iran has sent mixed signals about its intentions in recent days, with President Hassan Rouhani expressing a willingness to open new talks with Washington — once sanctions are removed.
“We are always ready for negotiation,” he said in a televised speech. “The moment you stop sanctions and bullying, we are ready to negotiate.”
But a spokesman for the Atomic Energy Organization of Iran, Behrouz Kamalvandi, said Monday that unless Europe could salvage the deal, his country would return its nuclear program to its status before the accord. Its uranium stockpile was much larger then, and some was much more highly enriched.
Tensions with Tehran have intensified since President Trump withdrew the United States from the accord in May 2018 and reimposed American economic sanctions that had been lifted under the deal. Mr. Trump imposed additional sanctions this year, trying to stop Iran’s ability to sell oil, a pillar of its economy.
Britain, France and Germany have made a commitment to ease the impact of American sanctions, but so far have not found an effective way.
The centerpiece of their efforts is the creation of a kind of exchange that would allow European companies to do business with Iran in a way that bypasses the American banking system. Tehran has said that the system, known as Instex, is inadequate.
Arriving at the meeting of Europeans on Monday, Josep Borrell, the Spanish foreign minister and nominee to become the European Union’s foreign affairs chief, said, “We will do what we can to guarantee that there is no economic embargo against Iran and that European companies can continue working there.”
“It’s very difficult because U.S. laws applied in an extraterritorial manner, in a way that we don’t recognize, make it difficult,” he said, adding that Spain would join the Instex mechanism.
Despite the renewed American sanctions, Iran complied with its commitments under the nuclear deal for a year after Mr. Trump’s withdrawal. But the confrontation has escalated since the American president imposed further sanctions.
Iran warned that it would stop complying with the deal’s caps on its enriched uranium stockpile unless the Europeans made good on their promises. The European countries were unable to deliver, and Iran surpassed the limits this month.
In May and June, six tankers were damaged near the Strait of Hormuz, the vital waterway that carries much of the world’s oil, and American officials said the ships had been attacked by Iran.
Last month, Iran shot down a United States surveillance drone, which American officials said was over international waters but which Tehran said had violated Iranian airspace. Mr. Trump ordered a military strike in retaliation, but then retracted the order.
This month, the British authorities seized an Iranian tanker near Gibraltar that they said was carrying oil to Syria, in violation of European Union sanctions on that country. Days later, London said that one of its naval ships had to chase away three Iranian boats that had been trying to impede a British tanker.
Britain offered on Saturday to return the Iranian ship if the oil were sent somewhere other than Syria.