Any military escalation in the Middle East should be censured, the UN chief said in a short statement issued by his spokesperson’s office.

“He is particularly concerned by Israeli attacks on nuclear installations in Iran while talks between Iran and the United States on the status of Iran's nuclear programme are underway,” said Farhan Haq, Deputy Spokesperson for the Secretary-General.

In an update on Friday, the head of the UN-backed atomic watchdog announced that the Iranian authorities had confirmed that the Natanz enrichment site had been “impacted” without affecting existing radiation levels.

The Iranian nuclear safety authorities also reported that the Esfahan and Fordow sites had not been impacted.

“This development is deeply concerning,” said Rafael Grossi, head of the International Atomic Energy Agency (IAEA).

“I have repeatedly stated that nuclear facilities must never be attacked, regardless of the context or circumstances, as it could harm both people and the environment. Such attacks have serious implications for nuclear safety, security and safeguards, as well as regional and international peace and security.”

According to reports, the Israeli military attacks targeted Iran’s nuclear programme at various sites across the country late Thursday.

Iranian media reported the death of Hossein Salami, chief of the country’s Revolutionary Guards, along with nuclear scientists.

The development comes as the United States was scheduled to begin a fresh round of negotiations with Tehran on Saturday in Oman. Israeli schools closed on Friday in anticipation of a retaliatory strikes by Iran, with reports that around 100 drones had been launched towards Israel in the early hours.

IAEA Director-General Grossi speaks on the situation in Iran: