In a confidential report issued on Thursday, the International Atomic Energy Agency (IAEA) warned that its inability to access facilities to verify nuclear materials in Iran is raising "proliferation concerns," while urging Tehran to cooperate "constructively."

The UN-affiliated agency has been unable to visit these sites since the war launched by Israel against Iran in June 2025, during which the United States joined the conflict by striking three major nuclear facilities.

These sites were also targeted during the war initiated by the United States and Israel against Tehran beginning on February 28.

The report stated that "while the agency acknowledges that military attacks on Iran's facilities and nuclear sites have created an unprecedented situation, conducting verification activities in Iran without delay is critical."

The report is scheduled to be discussed during a meeting of the agency's Board of Governors in Vienna next week.

According to the agency's estimates prior to the 2025 war, Iran possessed approximately 440 kilograms of uranium enriched to 60 percent purity, a level close to the 90 percent enrichment required for a nuclear weapon.

The current enrichment level also far exceeds the 3.67 percent limit established under the 2015 nuclear agreement, which became effectively void after the United States unilaterally withdrew from it in 2018.

In its report, the agency noted that its inability "to access and verify the previously declared stocks of highly enriched uranium and low-enriched uranium for nearly a year—a delay that significantly exceeds the timelines provided by normal safeguards practices—is a matter of proliferation concern."

IAEA Director General Rafael Grossi called on Iran to "engage constructively with the agency to facilitate the comprehensive and effective implementation of safeguards in Iran."

The United States, Israel, and several other countries have long accused Iran of seeking to develop a nuclear weapon, an allegation Tehran has consistently denied, insisting that its nuclear program is solely for peaceful purposes.