"The world has long agreed that Iran cannot be allowed to get a nuclear weapon, and we support action to prevent that. That is what this is," Prime Minister Anthony Albanese told a news conference.

"We don't want escalation and a full-scale war. We continue to call for dialogue and for diplomacy."

The prime minister stressed that the US attacks had targeted sites specific to Iran's nuclear program.

"Australia called upon Iran to come to the table and abandon any nuclear weapons program," Albanese said.

"Iran didn't come to the table, just as it has repeatedly failed to comply with its international obligations. We urge Iran not to take any further action that could destabilise the region."

Asked if Canberra had been advised in advance of the military operation, he said only that it was a "unilateral" action of the United States.

Australia's conservative opposition has also supported the US strikes, though the smaller Greens Party has condemned them as a "blatant breach of international law".

Australia's security strategy is deeply entwined with its relationship with long-time ally the United States.

In 2021, it joined with the United States and Britain in a multi-decade pact to equip the Australian navy with stealthy nuclear-powered submarines, seeking to balance China's growing military strength.