Fox said no matter how the investigation continues the answers will not come soon.
At a televised press conference on Saturday, Trudeau said he told Rouhani the admission was "an important step" but "many more steps must be taken". It said the missiles were launched in error. It denied those allegations but acknowledged seizing a British-flagged oil tanker in response to the impounding of an Iranian oil tanker by authorities in Gibraltar.
Iran's Judiciary Chief Ebrahim Raisi also promised Monday that "all material and moral rights of the victims and their families will be fully protected", the state news agency reported.
But many in Canada's political and military establishment see the events differently.
"There is no doubt this aircraft was brought down by a surface-to-air missile". "If it was, I think that's a starting gesture, but it's not enough".
"After we received confirmation from Tehran that they were waiting for us, this information was removed", Danilov said. The focus must now be on a transparent inquiry and cooperation with global authorities, especially the affected countries, who want a thorough investigation.
Canadian investigators flying to Tehran on Monday will access the rubble and black box from a Ukrainian jetliner that was hit by a missile attack last week. Canada's authority in the probe is fairly limited right now.
Nevertheless, safety board officials said the access granted by Iran to Canada has gone beyond what is required under worldwide protocols.
Fifty-seven of the victims were Canadians.
The Ukraine International Airlines flight crashed after takeoff from the airport in Tehran on Wednesday. Scores were Canadians, most believed to be dual nationals who had traveled to Iran to visit relatives there. Safety board experts skilled at analyzing voice and flight data recorders are ready to deploy, once they know where that work will be done.
Ms. Fox said the TSB is trying to gain the confidence of investigators in hopes of playing a bigger role.
Investigators will even look at Iran's assertion that the missile strike was accidental.
She said the TSB would not endorse the investigation if it concludes "there are serious problems with the report because it's either inaccurate or incomplete or misleading".
"Heightened military activity and increased political tensions in this region continue to pose serious threats to commercial vessels", the United States said in a maritime warning.
Ukraine's foreign minister said "grieving nations", five of the countries whose citizens were killed when an airliner was shot down, would meet on Thursday.
She cautioned that the investigation will not be short, but the outcome could help avoid a similar disaster in the future.