WASHINGTON — Iran announced on Monday that it would soon violate a central element of the 2015 agreement to limit its nuclear program unless it gets help from Europe to offset the effects of punishing American sanctions.
Iran’s Atomic Energy Organization said that within days it expects that the country will have produced and kept in its stockpiles more low-enriched uranium — the sort used to fuel power plants — than allowed by the 2015 deal, which the Trump administration withdrew from last year. The agency also left open the possibility that it might soon begin enriching the uranium to much higher levels of purity, edging it closer to what would be necessary to produce a nuclear weapon.
The White House responded with a call for greater international pressure on Iran. “President Trump has made it clear he will never allow Iran to develop nuclear weapons,” the National Security Council said in a statement.
The developments came at a time of escalating tensions between Washington and Tehran, and European officials urged restraint between the two longtime adversaries.
The announcement from Tehran was Iran’s latest signal that it will abandon the 2015 pact unless other signatories help Iran circumvent economic sanctions imposed by Mr. Trump. The threat seemed aimed primarily at European countries, to persuade them to break with Washington and swiftly restore some of the economic benefits of the deal to Tehran.
Iran had been abiding by the terms of the nuclear deal, negotiated under President Barack Obama, before Mr. Trump pulled out, and has continued to do so since the withdrawal by the United States. But as American sanctions have squeezed the Iranian economy, Tehran has warned that it could not remain in the deal without getting European help to find workarounds to the sanctions.
“This was an entirely predictable consequence of the Trump administration’s withdrawal from the nuclear deal and maximum pressure strategy,” said Ali Vaez, director of the Iran project at the International Crisis Group, a conflict-resolution organization. “In practice, maximum pressure has produced maximum peril and minimum strategic results.”
[The U.S. has turned up the pressure on Iran. See the timeline of events.]
The mechanism of American sanctions may actually have sped Iran to the point where its stockpile of uranium is on the verge of violating the 2015 agreement’s terms. In May, the State Department announced that it might penalize any country that transfers any enriched uranium out of Iran. Until now, Iran has shipped most of the low-enriched uranium it produces out of the country, swapping it for natural uranium. That allows it to continue producing token amounts of nuclear fuel for civilian power plants without building up a stockpile that might later be used in a weapons program.
During a news conference announcing Tehran’s decision, Behrouz Kamalvandi, a spokesman for Iran’s Atomic Energy Organization, said that Iran might also increase the level of uranium enrichment up to 20 percent for use in its reactors, the Iranian state-run news outlet Press TV reported.
He said that the uranium would be used as fuel for the Tehran Research Reactor, which the United States supplied to Iran in 1967. Iran says the facility is used to create medical isotopes for use in cancer treatment.
The nuclear agreement limits the level of enrichment to 3.67 percent, but if Iran began producing 20 percent enriched uranium, it would put the country much closer to weapons-grade levels.
Tensions between the United States and Iran have steadily increased since Mr. Trump withdrew the United States in May 2018 from the nuclear agreement that had been forged by the Obama administration, even though international energy experts said Iran was adhering to the deal.
Over the last year, the Trump administration imposed severe economic sanctions that have discouraged most outside companies from doing business with Iran, and followed that up with measures to cut off Iran’s revenues from oil sales, the lifeblood of its economy. The sanctions have had a great impact on Iran, including leading to a shortage of critical medicine within the country, despite Secretary of State Mike Pompeo’s assertions that humanitarian aid would not be affected. Arab militias in the region that receive support from Iran have suffered from a drop in financing.
Recent attacks on tankers in the Strait of Hormuz, which the Trump administration has blamed squarely on Iran, have further inflamed matters. And in April, Mr. Trump designated the Islamic Revolutionary Guards Corps, an arm of the Iranian military, as a foreign terrorist organization, despite warnings from Pentagon and C.I.A. officials that the move could lead to reprisals against Americans. As tensions rose, Mr. Trump said he was adding 1,500 troops to the Middle East.
A National Security Council spokesman said on Monday that Iran’s announcement on its nuclear program was “only possible because the horrible nuclear deal left the their capabilities intact.”
“The regime’s nuclear blackmail must be met with increased international pressure,” the spokesman, Garrett Marquis, said.
On Sunday, Mr. Pompeo said that the United States might further tighten sanctions on Iran in response to any moves to ramp up its nuclear program.
“We know that their nuclear program accelerates if they have more money and wealth, if they have more capacity, more resources, they have access to metals and to materials and to fissile material,” he said on “Face the Nation” on CBS.
Mr. Pompeo also said that the United States was considering “a full range of options” in responding to what the White House has said were Iranian attacks on tankers in the Strait of Hormuz. Those measures include but are not limited to military strikes, he said. Pressed on whether he thought an existing congressional authorization for war would cover hostilities with Iran, Mr. Pompeo avoided answering, as he did in April during a hearing on Capitol Hill.
Mr. Pompeo said he was making calls over the weekend to foreign officials to talk about the options. The United States has considered getting international support to create a naval force that would provide security for oil shipments in the region, similar to the antipiracy coalition assembled in the Arabian Sea in recent years.
“China gets over 80 percent of its crude oil transiting through the Strait of Hormuz,” Mr. Pompeo said. “South Korea, Japan, these nations are incredibly dependent on these resources. We’re prepared to do our part.”
China was an important contributor to the antipiracy venture, but may not be willing to join a United States-led effort to protect shipping. Beijing has opposed Mr. Trump’s Iran policies, has said it intends to continue buying oil from Iran despite American sanctions and is locked in a trade war with the Trump administration.
Mr. Kamalvandi, the spokesman for the Atomic Energy Organization, said that Iran’s low-enriched uranium stockpile would surpass a limit set in the agreement within the next 10 days, the semiofficial news agency Tasnim reported. Low-enriched uranium can be used in a nuclear reactor, but not in an atomic bomb.
He said, however, that Iran would stay within the limits if Britain, France, Germany and the full European Union — all of which are signatories to the nuclear deal — followed through on plans to give Iran access to international financial systems, sidestepping American sanctions, and also made up for lost oil revenue.
“As long as they comply by their commitments, these will go back,” Mr. Kamalvandi said in a televised news conference at the country’s Arak nuclear plant.
In early May, President Hassan Rouhani of Iran said his country would reduce compliance with the 2015 nuclear deal and take several steps to resume the production of nuclear centrifuges and begin accumulating more nuclear material if Europe did not put in place a barter system to ease the effects of American sanctions.
Germany, Britain and France have worked to set up a system to allow European companies to take part in a kind of barter trade with Iran.
The mechanism, called Instex or “Instrument in Support of Trade Exchanges,” is still in its early stages and relies on Iran to set up a similar system internally. But, at best, it is only a way to trade in goods not currently covered by the sanctions — including medical goods, food and humanitarian supplies.
At the time, Mr. Rouhani set a 60-day deadline for the Europeans, who hope to salvage the deal despite Mr. Trump’s opposition, to make good on promises to help preserve Iran’s oil and banking sectors. That deadline expires early next month.
But Mr. Rouhani was careful to maintain that while Iran would retain its enriched uranium and heavy water rather than selling them to other nations, the country, for the time being, would stay within the limits set by the nuclear deal.
Monday’s announcement was the first time Iran’s government had said explicitly that it would step beyond the pact.
The escalation comes as tensions between the United States and Iran continue to ratchet up, with the most recent confrontation coming over explosions on two tankers last week in the Strait of Hormuz.
President Trump called the incident a deliberate attack by Iran, and the United States released a video that it said showed an Islamic Revolutionary Guards Corps patrol boat pulling up alongside one of the stricken ships after the initial explosion and removing an unexploded limpet mine.
Iran called those accusations “warmongering” and part of a campaign of disinformation from the Americans. European officials have said the video is inconclusive and called for calm between the two nations.
A key Democrat, Representative Adam B. Schiff, the chairman of the House Intelligence Committee, has endorsed the conclusion that Iran attacked the tankers, but said the Trump administration’s escalating pressure campaign was backfiring.
“There’s no question that Iran is behind the attacks,” Mr. Schiff said Sunday on “Face the Nation.” “I think the evidence is very strong and compelling.”
American allies and intelligence agencies warned that “this kind of Iranian reaction was a likely result of a policy of withdrawing from the Iran nuclear agreement,” he said, adding that the administration’s approach had “only heightened the risk of conflict.”
If Iran did stop complying with the agreement, it would put pressure on the remaining signatories, which also include Russia and China, to join the United States in reimposing economic sanctions on Iran, which is hardly what Tehran wants to happen.
On Sunday, Helga Schmid, a senior Europe Union diplomat, visited Tehran for meetings on the nuclear deal. Ms. Schmid, who helped negotiate the 2015 agreement, reiterated her support for the deal, according to Reuters, and discussed options to enable trade between the bloc and Iran.
If Iran does break the limits of the deal, the Europeans will have to consider bringing the case to the United Nations Security Council and perhaps reimpose their own economic sanctions.
Meeting on Monday in Luxembourg, European Union foreign ministers called for further investigation of responsibility into the attacks on tankers in the Gulf of Oman last week.
The Netherlands’ foreign minister, Stef Blok, said European support for the Iran deal depended on Iran’s keeping to the pact’s terms.
“It’s very important to keep on verifying through the international atomic agency whether Iran is still fulfilling the criteria,” he said. “As long as Iran is fulfilling these criteria, we should stick to this deal.”