Iran has issued a warning against a potential censure resolution at the upcoming International Atomic Energy Agency (IAEA) Board of Governors meeting, as tensions escalate over its nuclear program.

Ali Shamkhani, a senior aide to Iran's Supreme Leader, who has been reportedly put in charge of Iran's nuclear negotiations, stated that Iran would deliver a "serious and effective response" if European nations pursue a resolution against its nuclear activities.

On his X social media account, Shamkhani criticized the plans of France, Germany, and Britain—collectively known as the E3—to propose a censure during the IAEA meeting, which coincides with the eve of Iran's presidential elections.

"If some misguided European countries intend to adopt a hostile stance towards Iran's peaceful nuclear program at the upcoming IAEA Board of Governors meeting, on the eve of Iran's presidential elections, they will face a serious and effective response from our country,” Shamkhani warned.

The development follows recent reports from The Wall Street Journal and Iran International that highlight the divide between Europe and the United States on how to handle Iran's nuclear advancements. While the Biden administration has urged the E3 to refrain from a rebuke that could heighten tensions, Reuters disclosed that the E3 appears determined to proceed with a draft resolution against Iran, signaling a possible rift among allies.

Two days after the WSJ report, a US official told Iran International on May 29 that the Biden administration is fully coordinating with its European allies to contain Iran’s nuclear program.

In an email statement, the US official said “we are increasing pressure on Iran through sanctions and international isolation as seen most recently in the coordinated G7 measures taken in the wake of Iran’s attack against Israel last month. No decisions have been taken with respect to the upcoming BOG," referring to the IAEA's Board of Governors' meeting from June 3 to 7.

The official added that Washington has kept the three European allies, also known as the E3, informed on its interactions with the International Atomic Energy Agency (IAEA) and on matters related to keeping pressure on Iran. Any allegation that the US is keeping its allies apprised, they said, is false.

Adding to the urgency, a confidential IAEA report accessed by several news agencies has exposed alarming details about Iran’s nuclear program. The report indicates that Iran’s stockpile of uranium enriched to 60% purity has reached 142.1 kilograms, close to weapons-grade levels and sufficient for several warheads if Tehran decides to build nuclear bombs. The highly enriched uranium has no credible civilian use.

In recent weeks, senior Iranian officials have threatened to reverse Tehran’s nuclear doctrine if threatened by an attack. The Islamic Republic has always insisted that its uranium enrichment program has purely civilian purposes and it has no intention to produce nuclear weapons.

Tensions have been high between the Islamic Republic and Israel since the October 7 Hamas invasion of Israel that killed more than 1,000 civilians. Sparking the Gaza war.