Canada on Tuesday dismissed as "nonsense" Tehran's insistence that only a few Canadians died last week when Iran shot down an airliner and demanded full accountability for what it called a horrible crime.
The remarks by Foreign Minister Francois-Philippe Champagne were some of the toughest from a Canadian official since the disaster in which 176 people died, 57 of them Canadian.
Iran, which does not recognise the concept of dual nationality, said last week that only a handful of victims were Canadian, according to officials in Ottawa.
"What I would say is it's nonsense ... we will not accept that position," Mr Champagne told the Canadian Broadcasting Corporation, saying he had raised the matter with Iranian Foreign Minister Mohammad Javad Zarif earlier in the day.
"We have already pushed back and been very, very clear to the Iranian regime that this is not going to hold. I think the world is watching and under the circumstances, I would expect, and I demand, that Iran would obviously respect what Canada wants when it comes to its own citizens."
Iran’s refusal to recognise dual nationality has caused numerous diplomatic crisis when people with second passports are detained in Tehran.
The UK government has demanded the release of Nazanin Zaghari-Ratcliffe, a British-Iranian detained on accusations of plotting to topple the government and sentenced to five years in prison. The British government rejects the charges, as do her family and lawyers.
However, Iran rejects questions being raised from the detainees’ government as it doesn’t see their involvement in the case as legitimate. Some dual nations have been denied consular access as a result.
It is unclear what Iran’s rejection of the dual-Canadian nationals’ passports will entail but it could raise issues with repatriation of remains to Ottawa and compensation being discussed for the families of the victims.
Prime Minister Justin Trudeau said on Saturday that Iran's admission it shot down the plane was an important step. Iran has granted visas for a Canadian team of investigators and consular officials.
Iran said on Tuesday it had arrested people accused of a role in shooting down the Ukrainian airliner and promised a thorough investigation.
"We are going to pursue full justice and we are going to make sure first we understand ... who committed this horrible crime and that these people are prosecuted in accordance with the highest standards of the law," said Mr Champagne, who did not give details.
Mr Champagne will preside over a meeting of his counterparts from Ukraine, Britain, Afghanistan and Sweden in London on Thursday to discuss their response. Canada has not had diplomatic relations with Iran since 2012.
Iran said on Tuesday it had arrested people accused of a role in shooting down a Ukrainian airliner and had also detained 30 people involved in protests that have swept the nation for four days since the military belatedly admitted its error.
However, a person who posted a video online last week showing a missile striking the plane has also been taken into custody by the elite Revolutionary Guards, the semi-official Fars news agency reported.
President Hassan Rouhani promised a thorough investigation into the "unforgivable error" in an address on Tuesday.
New security camera footage shows two missiles, fired 30 seconds apart, hitting the plane after take-off, the New York Times reported on Tuesday.
