Iranian nuclear sites "can't be destroyed with one attack and a few explosions," said Brigadier General Ebrahim Jabbari, adviser to Iran's Islamic Revolutionary Guard Corps, according to the state-aligned Tasnim news agency.

Trump promised he would finish the job in Iran and "get involved. So, what happened? You targeted commanders, but operational commanders emerged," Jabbari told Tasnim.

"You (Trump) said you have a drone and micro-drone division, but you didn't succeed. You said a split would form among the Iranian people, but it didn't. Instead, unity was created in Iran.

"There should be no doubt that the US failed in the Fordow attack, and the myth of bunker-buster bombs was shattered."

The IRGC is an elite wing of the Iranian military and was established in the aftermath of the country's revolution in 1979.

In 2019, the US put the Revolutionary Guards on its list of terrorist groups. The paramilitary organisation is not listed as a terror organisation in Australia

A US military official has told Associated Press that no American bases in Iraq were targeted.

There had been reports US assets in the country had been hit in Iran's overnight attacks, though Tehran did not claim responsibility.

However, the official said a malfunctioning Iranian missile aimed at Israel had triggered the alert in Iraq.

So what is the significance of the US base Iran attacked overnight?

Al Udeid Air Base in Qatar is a main regional military hub for US forces, which number 40,000 service members throughout the Middle East.

Al Udeid hosts thousands of US service members and served as a major staging ground for the wars in Afghanistan and Iraq.

At the height of both, Al Udeid housed some 10,000 US troops, and that number dropped to about 8000 as of 2022.

The forward headquarters of the U.S. military's Central Command, Al Udeid is built on a flat stretch of desert about 30km south-west of Qatar's capital, Doha.

Over two decades, the gas-rich Gulf country has spent some US$8 billion ($12.4 billion) in developing the base, once considered so sensitive that American military officers would say only that it was somewhere "in southwest Asia."

Trump visited the air base during a trip to the region last month.

It was the first time a sitting US president had traveled to the installation in more than 20 years.

Iran has taken a step closer to suspending cooperation with United Nations nuclear watchdog, the International Atomic Energy Agency, state media IRNA reported this morning.

Earlier in the day, the Iranian parliament's national security committee approved the outline of a bill that would do just that.

Speaker of Parliament Mohammad Bagher Ghalibaf said in a post on X:

"In the Islamic Consultative Assembly (Iranian parliament), we are pursuing the passage of a bill that would suspend Iran's cooperation with the International Atomic Energy Agency (IAEA) until concrete guarantees are provided regarding the agency's professional and unbiased conduct."

Committee spokesperson Ebrahim Rezaei said that the "general framework" was approved by the commission members, according to IRNA.

The bill will need to pass two additional hurdles before coming into law. First, it will have to be passed by parliament. Then, Supreme Leader Ayatollah Ali Khamenei will have to approve it.

Flights heading to the Middle East have been diverted or cancelled, causing travel chaos for Australians trying to head to the region for a holiday or stopovers to Europe.

Qatar's airspace was closed after attacks on a US air base in the country at 2.45am (AEST), diverting flights from dozens of airlines, including Qatar Airways, Emirates, Etihad and FlyDubai.

Qatar Airways has suspended all its flights, including those headed to European tourist destinations from Australia. 

Israeli officials are signaling that military operations in Iran could soon wind down.

Israel believes it can achieve its remaining military objectives in Iran in the coming days, which could tee up a ceasefire, an Israeli official told CNN.

Strikes on the bank of targets that intelligence services gathered are close to completion, the official said.

Israeli Prime Minister Benjamin Netanyahu said recently Israel is "very, very close to completing" its military objectives in Iran and made clear he does not want Israel to be dragged into a war of attrition with Iran.

Health Minister Mark Butler says the Australian government condemns Iran's attack on the US Al Udeid airbase in Qatar, and called on Tehran to return to the negotiation table.

"It's important for them, but also for the region and the broader international community that we see a de-escalation in this conflict," Butler told Today.

"Iran cannot be in a position where there's the threat of a full blown war or further escalation."

He affirmed Australia's support for US strikes on Iran's nuclear facilities.

About 3000 Australians in Iran and a further 1000 in Israel are seeking to leave the region.

"Our foreign affairs staff are working day and night to explore every possible opportunity to help Australians get out of there," Butler said.

Iran's Supreme Leader, Ayatollah Ali Khamenei, has also taken to social media overnight.

"We have not violated anyone's rights, nor will we ever accept anyone violating ours, and we will not surrender to anyone's violation; this is the logic of the Iranian nation," Khamenei wrote on his Farsi language X profile.

The post included a picture of a burning US flag.