Canadian Prime Minister Justin Trudeau says evidence indicates an Iranian missile downed the Ukrainian jetliner, and the strike may have been unintentional.

"Australia has received similar intelligence," Mr Morrison told reporters on Friday.

"This underscores the terrible nature of these events - all of that intelligence as presented to us today does not suggest an intentional act."

The evidence indicates the passenger plane was shot down by an Iranian surface-to-air missile, killing all 176 people on board, including at least 63 Canadians.

The prime minister would not clarify whether the shooting was a case of mistaken identity or a total accident altogether.

"It is difficult to come to the conclusion at this point that there was some sort of intentional act here," Mr Morrison said.

Australia has an embassy in Tehran and is working with the Canadian government to support families of those killed in the crash.

"It is a terrible, terrible event and we'll provide whatever support we can," Mr Morrison said.

The prime minister said it was critical a "full and transparent" investigation took place.

"That would include undertaking all efforts to ensure we get recovery of the black box recorder that can obviously inform that investigation," he said.

Australian Federal Police officers helped investigate the 2014 downing of Malaysian Airlines flight MH17 over eastern Ukraine.

Mr Morrison would not clarify exactly what assistance Australia was providing following this week's crash, instead saying Canada had an "open invitation" to whatever help it required.

The prime minister has spoken to Mr Trudeau and also plans to speak with his Ukrainian counterpart.

Australian Associated Press