US, Iran Meet in Rome with Nuclear Talks Under Strain

Washington insists that Tehran can’t continue to enrich uranium under a deal, warning that Iran’s ability to do so opens the way for the country to ultimately attain a nuclear weapon, which President Trump has vowed to prevent.

Iranian officials presented a united front this week, insisting that Tehran won’t bend its longstanding red line that it retain domestic enrichment. Iran spent days wavering over whether to attend the talks in Rome at all.

Iranian Supreme Leader Ayatollah Ali Khamenei, the country’s decision maker on security matters, predicted that talks will fail—his most antagonistic comments on diplomacy since discussions began on April 12.

Enrichment lies at the heart of the talks because the U.S. wants to cut off Iran’s ability to produce fissile material for a nuclear weapon. Iran claims its nuclear work is entirely peaceful. Western officials believe Tehran wants to enrich to retain the option of producing a nuclear weapon.

Trump had set a two-month deadline for how long talks should last, although it is not clear how hard that timeline is. U.S. officials have said Iran has been receptive to some of their ideas on a deal. Trump said last week a deal is close.

At stake in the talks is an agreement to roll back Iran’s nuclear program in exchange for lifting sanctions on its beleaguered economy. U.S. officials say Iran could build a bomb in a few months if it decides to. Trump has said a deal could open the way to significant U.S. trade with Tehran.

Iran has long insisted that any nuclear agreement must allow it to continue enriching fissile material, saying the country has the right to do so under international treaties. Iran was able to continue enriching under the 2015 nuclear deal, which Trump withdrew the U.S. from in 2018.

However, Iran’s enrichment goes far beyond its limited civilian nuclear needs. Iran has amassed enough near-weapons grade fissile material for at least seven nuclear weapons. It is the only country without a nuclear weapon to produce 60% enriched uranium.

This week, Israeli Prime Minister Benjamin Netanyahu swung behind the Trump administration’s goal of securing a deal where Iran couldn’t enrich uranium. Israel had previously called for a complete dismantlement of Iran’s nuclear program.

Israeli officials have warned they could act militarily to stop Iran building a bomb. Trump has said he prefers a deal but could order strikes on Iran if talks fail. Trump and Netanyahu discussed the negotiations in a call Thursday. White House spokeswoman Karoline Leavitt said afterward that the president believed talks are “moving along in the right direction."

Washington and Tehran have floated ideas to narrow the gap over enrichment, although only some have been discussed in talks.

The U.S. has said it is all right with Iran having a civilian nuclear program for energy but it wants Iran to import the enriched uranium from abroad. It delivered its first proposal for a deal in the last round of talks.

“We’ve delivered a proposal to the Iranians that we think addresses some of this without disrespecting them," Steve Witkoff, U.S. chief negotiator and special envoy to the Middle East, said Sunday.

Iranian officials, including its top negotiator, Foreign Minister Abbas Araghchi, have said Iran could take confidence-building steps by ending its production of highly enriched uranium and handing over its stockpile. Iran has dismissed an idea floated by European countries to stop enrichment for a few years.

Araghchi said Iran would welcome U.S. investment in Iran’s civilian nuclear program following a deal, potentially giving Washington greater visibility of Iran’s program. Any sharing of U.S. nuclear material or technology would face significant political and legal hurdles in Washington.

Iranian officials have also revived an old idea, saying they could explore a nuclear consortium with regional neighbors, including Saudi Arabia. That could see the countries share some technology and permit foreign engineers in Iranian facilities, officials say.

But Araghchi said on the eve of the Rome talks the consortium idea would come on top of Iran’s domestic enrichment program, not replace it. U.S. officials say the idea hasn’t been broached in talks.

The U.S. has had talks on a regional fuel arrangement with Gulf countries, which could provide nuclear fuel for civilian energy programs. But the idea is that the countries wouldn’t enrich uranium.

The idea of Iran shipping out its fissile material has also been proposed in the past, with Tehran receiving reactor fuel in return. But those discussions never stuck.

Former Western officials say another proposal discussed in previous negotiations could be worth resurfacing. It would see Iran stop enriching uranium but be fitted out with the ability to fabricate nuclear fuel for civilian reactors, using imported enriched uranium.

That is a capability it doesn’t currently have and would allow Tehran to argue it was still carrying out a key part of its nuclear work at home, but it would prevent it gathering the fissile material needed for a nuclear bomb.

For now, that doesn’t seem to be an option. “Figuring out the path to a deal is not rocket science: Zero nuclear weapons = we DO have a deal. Zero enrichment = we do NOT have a deal," Araghchi said on X before flying to Rome.

Write to Laurence Norman at laurence.norman@wsj.com and Benoit Faucon at benoit.faucon@wsj.com