Iran's Foreign Minister Abbas Araghchi wrote to the UN Secretary General and Security Council on March 22 detailing what he described as illegal US-Israeli military attacks on two Iranian nuclear facilities, calling for "immediate and decisive action" from the UN and IAEA, IRNA reported.

The letter listed three specific attacks on safeguarded nuclear sites since the war began: two strikes on the Natanz enrichment facility on March 1, a strike on a building 350 metres from the operating Bushehr nuclear reactor on March 17, and a further bombardment of multiple points at Natanz on March 21.

Araghchi cited previous warnings from IAEA Director General Rafael Grossi that nuclear facilities "must never be attacked, regardless of context or circumstances."

He quoted Grossi's statement to the Security Council that a direct hit on Bushehr "could lead to a very high release of radioactive materials into the environment" and that knocking out the plant's two power supply lines could cause a reactor core meltdown.

The letter argued that the strikes constituted a violation of Article 2(4) of the UN Charter prohibiting the use of force, the IAEA Statute and a peremptory norm of international law from which no derogation is permitted.

Araghchi said the US and Israel bore international responsibility for "a war of aggression" and that individuals who effectively controlled or directed the political or military actions bore individual criminal responsibility.

He called on all states to "cooperate through lawful means to bring such serious breaches to an end."

The letter came as Trump gave Iran a 48-hour ultimatum to reopen the Strait of Hormuz or face strikes on its power plants. Iran's parliament speaker warned any such attack would trigger "irreversible" destruction of Gulf energy infrastructure.