Canadian Prime Minister Mark Carney said Thursday that he couldn't rule out his country's military participation in the escalating war in the Middle East.

Carney's visit to Australia this week has been overshadowed by expanding war in the Middle East, sparked by a massive US-Israeli strike on Iran that killed its supreme leader, Ayatollah Ali Khamenei.

Speaking alongside local counterpart Anthony Albanese in Canberra, Carney was asked whether there was a situation in which Canada would get involved.

"One can never categorically rule out participation," he said, while stressing the question was a "hypothetical" one.

"We will stand by our allies," said Carney, adding that "we will always defend Canadians."