UPDATED 8.30AM TUESDAY (AEST)

US President Donald Trump has announced a “complete and total” ceasefire between Israel and Iran.

“It has been fully agreed by and between Israel and Iran that there will be a Complete and Total CEASEFIRE… for 12 hours, at which point the War will be considered, ENDED!,” Trump wrote in a post on Truth Social early on Tuesday (Australian time).

“On the assumption that everything works as it should, which it will, I would like to congratulate both Countries, Israel and Iran, on having the Stamina, Courage, and Intelligence to end, what should be called, ‘THE 12 DAY WAR’,” he wrote.

Trump’s announcement came after Iran’s military said it had carried out a “devastating and powerful” missile attack on the Al-Udeid US air base in Qatar.

Neither Iran nor Israel has yet commented on Trump’s ceasefire announcement.

He earlier thanked Iran for giving the US notice prior its attack on the military base, which he said made it possible for no lives to be lost.

“Perhaps Iran can now proceed to Peace and Harmony in the Region, and I will enthusiastically encourage Israel to do the same,” Trump wrote.

Qatar’s defence minister, quoted by al-Jazeera TV, said its air defences had intercepted missiles directed at the Al-Udeid air base.

The base, which is across the Persian Gulf from Iran, is the largest US military installation in the Middle East.

Qatari authorities said there were no casualties in the attack, which it condemned and said it reserved the right to respond.

US officials also said there had been no US casualties.

The attack came shortly after Qatar closed its airspace as a precaution and the US and Britain urged their citizens in the country to “shelter in place”.

Iran co-ordinated its strikes on US bases, prompting the air space closure, a source familiar with the matter told Reuters on Monday.

The New York Times, which first reported the co-ordination, said Iran took the action to minimise casualties.

Just before the explosions, Iranian President Masoud Pezeshkian wrote on the social platform X: “We neither initiated the war nor seeking it. But we will not leave invasion to the great Iran without answer”.

The Al-Udeid Air Base in Qatar is the forward headquarters for US Central Command. Photo: AAP

In addition, the US Ain al-Asad air base in Iraq had activated its air defence system amid fears of a potential attack, military sources told Reuters.

Ebrahim Zolfaqari, a spokesman for Iran’s Khatam al-Anbiya central military headquarters, issued an apparent threat to retaliate after Trump approved attacks on Iranian nuclear sites at Fordow, Natanz and Isfahan.

“Mr Trump, the gambler, you may start this war but we will be the ones to end it,” Zolfaqari said on Monday in an English-language video statement.

Earlier on Monday, Israel bombed a jail for political prisoners in Tehran in a potent demonstration that it was expanding its targets beyond military and nuclear sites to aim squarely at the pillars of Iran’s ruling system.

Despite Iran’s threats to challenge oil shipments from the Gulf, oil prices largely held steady, suggesting traders doubted Iran would follow through on any action that would disrupt global supplies.

Iranian Foreign Minister Abbas Araqchi met Russian President Vladimir Putin in Moscow as Iran sought backing from one of its last major power friends for its next steps.

Trump’s administration maintains that its aim is to destroy Iran’s nuclear program, not to open a wider war.

The US administration says it is still seeking a diplomatic resolution that would have Iran forgo any reprisal.

-with AAP