Canadian Prime Minister Justin Trudeau has joined other allies including the US and Australia to say it was highly likely an Iranian anti-aircraft missile downed a jetliner near Tehran this week, killing all 176 people on board.

With at least 63 Canadians on board the Ukraine International Airlines jet, Mr Trudeau told reporters on Friday morning (AEST):

"The evidence indicates that the plane was shot down by an Iranian
surface-to-air missile. This may well have been unintentional.

"This new information reinforces the need for a thorough investigation into this matter," he said.

The ABC reported Mr Morrison told Sydney Radio 2GB "he can confirm that Australia has had similar intelligence to Canada and the US".

The catastrophic incident came just a few hours after Iranian forces fired more than a dozen missiles at military bases housing US troops in Iraq.

The missile attack followed a confrontation with Washington over the US drone strike that killed an Iranian Revolutionary Guard general last week.

One US official, speaking on condition of anonymity, said US satellites had detected the launch of two missiles shortly before the plane crashed, followed by evidence of an explosion.

Speaking to reporters, US President Donald Trump said the crash could have been a mistake, adding he had a terrible feeling about the downed airliner but offered no evidence.

Mr Trump dismissed Iran's claims that the cause was a mechanical issue – and denied any US responsibility.

"Somebody could have made a mistake on the other side," he said, noting the plane was flying in a "pretty rough neighbourhood".

"Some people say it was mechanical … I personally don't think that's even a question."

The Boeing 737-800 was carrying 82 Iranians, 63 Canadians, 10 Swedes, four Afghans, three Germans, and three British nationals. The remaining eleven people killed in the fiery crash are Ukrainians.

Iran’s aviation authority has refused to hand over flight recorders from the plane, either to the aircraft’s manufacturer or US aviation authorities.

US Secretary of State Mike Pompeo on Thursday said the United States was calling for complete co-operation with any investigation into cause.

Evidence shows missile downed jet_1
Inset: The Ukrainian Boeing 737-800 plane that crashed near Tehran. Photo: AAP

Under international rules, responsibility for investigating the crash lies with Iran. Iranian state television said both of the plane’s black box voice and data recorders had been found.

Immediately after the crash, Iran’s semi-official Fars news agency attributed the airliner's plunge into a field outside the Tehran to “technical problems” – an explanation that surprised experts who noted the aircraft’s black boxes had not yet been recovered and that such investigations usually take months to reach a determination.

Ukraine officials initially endorsed the diagnosis of mechanical failure, only to change their minds within hours, saying they had not ruled out the possibility that the airliner was brought down by a missile or an attack.

They noted that the plane, one of Boeing’s most reliable models, had been serviced within the past week and was only three years old.

-with AAP