The United States and Iran were meeting in Geneva on Thursday for high-stakes nuclear talks as President Donald Trump pressures Tehran with the threat of military action.
The talks — a third round of indirect negotiations — come after Trump made his clearest case yet for a possible attack as he oversees a sweeping military buildup in the region.
Trump declared in his State of the Union address that Iran was working to develop missiles that could “soon” reach the U.S. and that it was trying to restart its nuclear program, which was battered by American and Israeli strikes last year.
"The principle is very simple: Iran cannot have a nuclear weapon," Vice President JD Vance said at a news conference Wednesday.
"If they try to rebuild a nuclear weapon, that causes problems for us," he said, adding that Washington had "seen evidence that they have tried to do exactly that.”
Iran has consistently denied seeking to develop a nuclear weapon, and has warned of an intense response to even a limited attack by the U.S. or Israel.
Tehran dismissed Trump's claims that it had "sinister nuclear ambitions" as part of a series of "big lies."
The talks come as the U.S. carries out an intensive military buildup in the Middle East, its biggest in decades, while the president weighs options for possible attacks.
Trump's assertion that Iran was seeking to build a missile that could reach the U.S. comes after weeks of mixed messages from Washington on the reasons for the military buildup.
The president had initially threatened to intervene amid a deadly crackdown on nationwide unrest in Iran last month, but his administration's threats have in recent weeks centered on the Islamic Republic's nuclear program, which he has simultaneously maintained was "obliterated" in U.S. strikes last June.
Trump said Tuesday that while that operation was successful, Tehran had been "starting all over."
Secretary of State Marco Rubio elaborated on the subject Wednesday. He told reporters that Iran is “always trying to rebuild elements” of its nuclear program. Tehran is not enriching uranium right now, he said, “but they’re trying to get to the point where they ultimately can."
In addition to commitments on enrichment, the U.S. has been pushing for Iran to make concessions on its ballistic missile program and its support for militant forces across the Middle East.
Iran has insisted the talks must remain focused on nuclear issues.
They are being mediated by Oman, a key regional interlocutor.
Omani Foreign Minister Badr al-Busaidi said the two sides had shown “openness to new and creative ideas” after meeting with Trump’s son-in-law Jared Kushner and special envoy Steve Witkoff.
In a later post on X, he expressed optimism during a break in talks, saying "creative and positive ideas" had been exchanged and "we hope to make more progress."
Negotiations were set to resume later Thursday after the break, he said.
Iran’s proposals have not been made public, but it has emphasized it expects the lifting of sanctions in return for possible concessions on its nuclear program.
On the eve of the talks, the Trump administration imposed fresh sanctions over the country’s oil exports and ballistic missile production.
"Our Supreme Leader has already said that we will not have nuclear weapons at all," Iranian President Masoud Pezeshkian said, asserting: "The leader of a society, a religious leader of a community, cannot lie."
Foreign Ministry spokesman Esmail Baghaei told state TV early Thursday that “Iran has entered the negotiations with full preparedness and seriousness.”
