The U.N. nuclear watchdog's 35-nation Board of Governors passed a resolution on Thursday formally declaring Iran in breach of its non-proliferation obligations for the first time in almost 20 years, diplomats at the closed-door meeting said.

In a closed-door session in Vienna, the IAEA’s 35-member board adopted a resolution against Iran by a vote of 19 in favor, 3 opposed, and 11 abstaining. The resolution states that Iran is in non-compliance with its safeguards commitments under the Nuclear Non-Proliferation Treaty (NPT), particularly in relation to undeclared uranium traces found at multiple sites.

Diplomatic sources said the resolution reflects growing frustration over Iran’s lack of transparency, especially as the country expands uranium enrichment up to 60% purity.

Switzerland Urges Cooperation

Swiss Ambassador Matteo Fachinotti, the country’s envoy to the IAEA, called for a renewed commitment to diplomacy. “Switzerland calls on Iran to cooperate with the IAEA to resolve outstanding issues,” he wrote on X. “A successful outcome of ongoing diplomatic efforts is more important than ever.”

Switzerland has historically played a neutral mediation role between Iran and Western powers.

Tensions Rise Ahead of New Talks

The resolution comes just days before a new round of indirect US-Iran nuclear negotiations is expected to take place in Muscat. It also follows President Trump’s public warnings that Iran’s red lines on enrichment could derail talks.

While Iran has denounced such resolutions as politically motivated, IAEA Director General Rafael Grossi has repeatedly warned that the agency cannot verify the peaceful nature of Iran’s nuclear program without full cooperation.