E3 Set to Trigger UN Sanctions Snapback on Iran Over Nuclear Violations

Britain, France, and Germany — collectively known as the E3 — are expected to begin the process of reimposing United Nations sanctions on Iran as early as today, unless Tehran resumes cooperation with international nuclear inspectors and returns to the negotiating table.

The move would mark a significant escalation in efforts to enforce the terms of the 2015 nuclear agreement, which aimed to prevent Iran from developing nuclear weapons. The original deal saw wide-ranging U.N. sanctions lifted, but the E3 now accuses Iran of breaching its obligations, particularly with uranium enrichment far beyond civilian energy needs — a claim Tehran denies.

“If Iran is not willing to reach a diplomatic solution before the end of August 2025, or does not seize the opportunity of an extension, E3 is prepared to trigger the snapback mechanism,” the E3 foreign ministers wrote to the U.N. Security Council last week.

The snapback mechanism, if activated, would restore U.N. sanctions within 30 days, targeting Iran’s financial, banking, energy, and defense sectors.

Although E3 officials met Iranian representatives in Geneva on Tuesday, European and Western diplomats say the talks failed to produce “sufficiently tangible commitments” from Tehran. One Western diplomat noted that while formal negotiations may follow, “the real negotiations will start once the letter [to the Security Council] is submitted.”

A spokesperson for the German Foreign Ministry confirmed that triggering the snapback “remained an option”, reinforcing the E3’s readiness to act if diplomacy continues to stall.

In a sign of potential de-escalation, the E3 has offered to delay the sanctions snapback for up to six months — but only if Iran agrees to resume full cooperation with U.N. inspectors and re-engages in talks with the United States. This would include granting access to inspect Iran’s current stockpile of enriched uranium, which has not been fully verified since Israeli airstrikes on June 13.

According to the International Atomic Energy Agency (IAEA), Iran had already enriched uranium up to 60 percent purity — just a step below weapons-grade — and had stockpiled enough for six nuclear weapons before the June attacks.

While IAEA chief Rafael Grossi confirmed that inspectors have now returned to Iran, he cautioned that no agreement had been reached on their level of access or activities.

Iranian Foreign Minister Abbas Araqchi told lawmakers that Tehran has yet to agree on how to fully resume cooperation with the nuclear watchdog, according to parliament news agency ICANA.

Meanwhile, Iran has issued a stern warning, vowing a “harsh response” if U.N. sanctions are reimposed.