Rafael Grossi, the head of the United Nations’ International Atomic Energy Agency (IAEA), cautioned on Tuesday that options for resolving issues around Iran’s nuclear program are "beginning to shrink." Grossi, speaking at the COP29 summit in Baku, emphasized the importance of diplomatic solutions as he prepared for a pivotal trip to Tehran.

"The Iranian administration must understand that the international situation is becoming increasingly tense and that the margins to manoeuvre are shrinking," Grossi told AFP. He underscored that the IAEA needs "greater visibility" into Iran’s activities, given the scale and ambition of its nuclear program.

Grossi’s trip to Iran follows the re-election of Donald Trump, who famously withdrew the United States from the 2015 nuclear accord, a deal brokered under former President Barack Obama. Grossi expressed confidence in continuing cooperation, stating, "I already worked with the first Trump administration and we worked well together."

The 2015 agreement, also involving Russia, China, the UK, France, and Germany, was designed to limit Iran’s nuclear activities and subject them to rigorous inspections, in exchange for sanctions relief. However, with the U.S. exit from the agreement in 2018, attempts to revive the accord have stalled. Grossi described the agreement as "an empty shell" due to failed efforts to reestablish its framework.

Since the deal’s collapse, Iran has significantly expanded its nuclear program, amassing uranium enriched to 60%, close to the 90% level needed for nuclear weapons. Although Iran denies intentions of weaponization, the program’s advancements have drawn concern globally.

Encouragingly, Iran’s new reformist president, Masoud Pezeshkian, has signaled openness to resuming talks to restore the deal. Grossi’s last visit to Iran, in May, involved an inspection of the Natanz uranium enrichment facility, during which he urged Iranian leaders to take "concrete" steps to address international concerns.