It comes after Israel last week began launching strikes on Iran's nuclear facilities, alleging that that the country was seeking to develop nuclear weapons -- an accusation Tehran has always denied.

The International Atomic Energy Agency (IAEA) has said that a key above-ground component of the Natanz site where Iran was producing uranium enriched to up to 60 percent -- short of the 90 percent required to produce weapons-grade material -- had been destroyed in the attacks.

Addressing an extraordinary board meeting on Monday, IAEA chief Rafael Grossi said there has been "no additional damage" at the Natanz site since Friday.

Radioactivity levels outside the Natanz plant "remained unchanged and at normal levels, indicating no external radiological impact", Grossi added.

Furthermore, there has been "no indication of a physical attack on the underground cascade hall containing part of the Pilot Fuel Enrichment Plant and the main Fuel Enrichment Plant", he said in his statement.

"However, the loss of power to the cascade hall may have damaged the centrifuges there," he added.

Iran's ambassador to the IAEA, Reza Najafi, called on the board members to "condemn Israeli aggression in its strongest terms and hold it accountable".

"Otherwise, consequences would be with those appeasing," he added.

Najafi told reporters that Iran has urged the Board of Governors and the IAEA "not to allow their initial failure to prevent aggression to be followed by subsequent failure and to take a strong and effective remedial action" at Monday's urgent session.

"For the second time in three years, we are witnessing a dramatic conflict between two IAEA member states in which nuclear installations are coming under fire and nuclear safety is being compromised," Grossi warned.

He said the IAEA, sa in the war in Ukraine, would "not stand idly by during this conflict", offering his assistance to Iran.