The UN Security Council has met to discuss US strikes on Iran’s nuclear sites as Russia, China and Pakistan proposed the 15-member body adopt a resolution calling for an immediate and unconditional ceasefire in the Middle East.

It was not immediately clear when it could be put to a vote.

The three countries circulated the draft text on Sunday, said diplomats, and asked members to share their comments by Monday evening.

A resolution needs at least nine votes in favour and no vetoes by the United States, France, Britain, Russia or China to pass.

The US is likely to oppose the draft resolution, seen by Reuters, which also condemns attacks on Iran’s nuclear sites and facilities. The text does not name the United States or Israel.

“The bombing of Iranian nuclear facilities by the United States marks a perilous turn in a region that is already reeling,” UN Secretary-General Antonio Guterres told the Security Council on Sunday.

“We now risk descending into a rathole of retaliation after retaliation.”

“We must act – immediately and decisively – to halt the fighting and return to serious, sustained negotiations on the Iran nuclear program.”

The world awaited Iran’s response on Sunday after President Donald Trump said the US had “obliterated” Tehran’s key nuclear sites, joining Israel in the biggest Western military action against the Islamic Republic since its 1979 revolution.

UN nuclear watchdog chief Rafael Grossi told the Security Council that while craters were visible at Iran’s enrichment site buried into a mountain at Fordow, “no one – including the IAEA – is in a position to assess the underground damage”.

Grossi said entrances to tunnels used for the storage of enriched material appear to have been hit at Iran’s sprawling Isfahan nuclear complex, while the fuel enrichment plant at Natanz has been struck again.

“Iran has informed the IAEA there has been no increase in off-site radiation levels at all three sites,” said Grossi, who heads the International Atomic Energy Agency.

Iran requested the UN Security Council meeting, calling on the 15-member body “to address this blatant and unlawful act of aggression, to condemn it in the strongest possible terms.”

Israel’s UN Ambassador Danny Danon said in a statement on Sunday that the US and Israel “do not deserve any condemnation, but rather an expression of appreciation and gratitude for making the world a safer place.”

Danon told reporters before the council meeting that it was still early when it came to assessing the impact of the US strikes. When asked if Israel was pursuing regime change in Iran, Danon said: “That’s for the Iranian people to decide, not for us.”

—AAP