The fifth round of nuclear negotiations between the United States and the Islamic Republic of Iran concluded on May 23, 2025, in Rome. Despite ongoing mediation by Oman, significant gaps remain, particularly regarding uranium enrichment. With the expiration of the UN sanctions "snapback" mechanism approaching in October, the window for meaningful diplomacy narrows rapidly, underscoring the critical importance of the next steps.

The Bottom Line

The latest round of nuclear talks ended with minimal tangible progress. Fundamental differences persist, with Tehran refusing to halt enrichment, insisting it is a sovereign right, while Washington demands zero enrichment.
- Islamic Republic foreign minister and lead negotiator Abbas Araghchi bluntly summarized the regime's position on May 9, asserting, “Iran categorically refuses zero enrichment.”

President Trump expressed guarded optimism publicly but simultaneously reaffirmed the U.S. stance on zero enrichment, underscoring potential military consequences if negotiations fail.
- Trump stated on May 25, “I don't know if I'll be telling you anything good or bad over the next two days, but I have a feeling I might be telling you something good."
- Both Tehran and Washington face mounting domestic and international pressures that could force a diplomatic breakdown.

Negotiations and Current Realities

The recent round of talks in Rome, though labeled productive by mediators, failed to bridge core disagreements. Oman’s Foreign Minister Badr al-Busaidi noted the session ended with "some but not conclusive progress.”
- On May 26, Tehran rejected reports of a potential interim deal or break in enrichment in order to move closer to a nuclear deal with the United States.
- Esmaeil Baqaei, spokesperson for the Islamic Republic’s Foreign Ministry, firmly dismissed the idea of an interim agreement, stating unequivocally that Iran "will never agree to that." He emphasized that “under no circumstances will Iran consider a temporary suspension of uranium enrichment.”

The Islamic Republic’s ongoing enrichment activities and accumulation of highly enriched uranium (HEU) at 60% purity further complicate negotiations, signaling Tehran's potential brinkmanship strategy. The regime has now stockpiled over 270 kg of uranium enriched to 60% purity, an unprecedented quantity for a non-nuclear weapon state, heightening proliferation concerns.

U.S. negotiators, led by Special Envoy Steve Witkoff, maintain a firm stance on zero enrichment, emphasizing the existential proliferation risks posed by any enrichment.
- Witkoff explicitly stated on May 9, “An enrichment program can never exist in the state of Iran ever again; that’s our red line.”
- Rubio acknowledged the complexity of negotiations on May 20, stating efforts to strike a deal that allows Iran a peaceful civilian nuclear energy program but no uranium enrichment would “not be easy,” adding, “any enrichment positions Iran dangerously close to weaponization.”
- Rubio also asserted that if the deal fails to address “Iran’s sponsorship of terrorism and violations of weapons conventions, including its long-range munitions programs, related sanctions will remain in place.”

Supreme Leader Ayatollah Khamenei categorically rejected zero enrichment demands, calling them “way out of line,” adding, "No one is waiting for permission from anyone. The Islamic Republic has its own policies and pursues its own agenda."

Regional and International Dynamics

European allies (E3: Britain, France, Germany), publicly supportive of diplomacy, have indicated readiness to reimpose UN sanctions through snapback provisions if no concrete agreement emerges soon. France specifically warned it “will not hesitate to reimpose UN sanctions if diplomacy fails.”
- U.S. Secretary of State Marco Rubio’s Senate testimony last week captured this shift. Rubio noted that aside from U.S. efforts, “there’s a separate set of sanctions out there, which are the snapback provisions that the E3 in Europe have… They are moving forward on their process, independent from ours.” In other words, Britain, France, and Germany are preparing to trigger UN sanctions on their own timeline, likely well before the October deadline, regardless of U.S. domestic deliberations.

Russia and China continue providing strategic diplomatic and economic backing to Tehran.
- Any attempt to reimpose UN sanctions following October 18, 2025, would require passing a new Security Council resolution, which would likely be vetoed by Russia and/or China.
  - Learn more about the snapback mechanism by reading NUFDI’s policy brief: How Does the E3 Initiate Snapback Sanctions?

Israel remains staunchly opposed to any agreement short of complete dismantlement, openly preparing military contingencies against the Islamic Republic’s nuclear facilities. Prime Minister Benjamin Netanyahu has advocated for a “Libya model” solution—complete nuclear dismantlement in exchange for normalization—and warned against partial measures.
- On May 24, Israeli Minister for Strategic Affairs Ron Dermer met with Steve Witkoff and other U.S. officials. On May 25, the director of the Israeli intelligence agency Mossad, David Barnea, traveled to Washington to join Dermer and met with the head of the Central Intelligence Agency, John Ratcliffe.

President Trump reportedly cautioned Israeli Prime Minister Benjamin Netanyahu not to take any action that could jeopardize negotiations.

On May 22, Araghchi issued a formal letter to the UN, warning that the Islamic Republic “will respond decisively to any threats or unlawful actions by .” He further added that “if any attack is carried out … by the Israeli regime, the U.S. government will be complicit and bear legal responsibility.”

IAEA and Verification Challenges

The International Atomic Energy Agency (IAEA) continues to face severe challenges verifying the Islamic Republic's nuclear activities due to Tehran's removal of inspectors and surveillance equipment. Director General Rafael Grossi emphasized the urgent need for “robust verification,” warning previously that the IAEA “lost continuity of knowledge” regarding the regime’s nuclear activities.

The Islamic Republic’s reluctance to provide comprehensive explanations for uranium traces at undeclared sites further exacerbates verification concerns. Grossi stressed, “Without us, any agreement on Iran is just a piece of paper,” underscoring Tehran's strategic opacity and verification barriers.

Strategic and Military Risks

The Trump administration maintains a robust military posture in the Persian Gulf, signaling that military options remain on the table should diplomacy collapse. President Trump warned explicitly that the regime in Iran will “face military action” if it fails to accept a satisfactory deal.
- Israel’s explicit preparations for unilateral strikes on the Islamic Republic’s nuclear facilities significantly strengthen the U.S. negotiating position, emphasizing that diplomacy is not the only solution to the nuclear threat emanating from the regime in Iran.

Islamic Republic leadership, including President Masoud Pezeshkian and Supreme Leader Khamenei, increasingly highlight national resilience and potential escalation. Pezeshkian asserted on May 26, “We will not die of hunger if refuse to negotiate or impose sanctions. We will find a way to survive,” and directly addressed U.S. pressure, stating, “You came to frighten us? We will not bow to any bully.”

Tehran's Saber-Rattling

Over the past few weeks, senior Islamic Republic military commanders have also issued warnings against any potential attack on nuclear facilities in Iran. The threats crescendoed to a new high on May 22, a day before the last round of the talks.
- Spokesperson for the Islamic Revolutionary Guard Corps (IRGC), Brig. Gen. Mohammad Ali Naini said, “The enemy is deluded in its assessment of our national resolve. If war breaks out, they will witness the same mobilization of people that occurred during the eight-year Iran-Iraq War… If the Zionist regime makes the mistake of launching an attack, it will undoubtedly receive a crushing and destructive response within its small and vulnerable geography.”
- The commander of the regime’s conventional ground forces (Artesh Ground Forces), Brig. Gen. Kioumars Heydari stated, “Our forces stand with eyes wide open and fingers on the trigger, awaiting the commands of the Supreme Leader… Any miscalculation by enemies will be met with unmatched power and decisive retaliation.”
- Chief of Staff of the Armed Forces Maj. Gen. Mohammad Hossein Baqeri said, “My companions and I inspected different branches of the armed forces units over the past 48 hours. The armed forces are at peak readiness.”
- On the same day, the Artesh Ground Forces unveiled three new drones, namely Homa, Dideban, and Shahin-1 FPV suicide drones, at a southeastern drone and air base.
- On May 25, IRGC Commander-in-Chief Maj. Gen. Hossein Salami said that Iran “is currently engaged in an all-out war”, but there are “no signs of turmoil or fear in the country.”

Policy Recommendations

Sustain and intensify maximum pressure through rigorous sanctions enforcement, explicitly linking any potential relief to negotiation red lines, including zero enrichment.

Strengthen diplomatic coordination with European allies (E3) and regional partners, particularly Israel, to reinforce unified messaging and cohesive strategies against the Islamic Republic’s nuclear advances.

Formulate a robust contingency plan (“Plan B”) to swiftly implement enhanced sanctions and provide Maximum Support to the Iranian people.