LONDON - Iran's president levelled threats Wednesday against Europe in response to European countries' new crackdown on his country's violations of their nuclear deal - a move Canada is also supporting.

The escalation of rhetoric over the nuclear deal is casting a shadow over an international meeting that Canada hopes will lead to justice and financial compensation for the families of the victims of Iran's shooting down of a Ukrainian airliner.

Foreign Affairs Minister Francois-Philippe Champagne arrives in London later today for a meeting Thursday of the International Co-ordination and Response Group for families of victims of Flight PS752, which Iran downed last week killing all 176 people on board, including 57 Canadians and 82 Iranians.

The Canadian Press has independently confirmed at least 89 victims with ties to Canada, many of them students and professors returning after spending the December break visiting relatives in Iran.

The meeting at the Canadian High Commission will include representatives of Ukraine, Sweden, Afghanistan and Britain, and is being billed by Ottawa as a step towards “closure, accountability, transparency and justice - including compensation - for the families and loved ones of the victims.”

As attendees gathered, Canada demanded official status in Iran's investigation of the crash.

In a news conference in Ottawa, Transport Minister Marc Garneau said two Canadian investigators are in Iran as part of an international team and have been getting good co-operation, but he wants their participation in the probe formalized.

“We will not accept a situation where we are not being given the information we are looking for,” Garneau said.

He said the plane's “black boxes” are in Iranian hands and another two investigators are ready to go wherever and whenever the recorders are examined. He said he has seen a video recording - publicized by the New York Times - showing what appear to be two separate missiles targeting the plane, not just one, and that's exactly the kind of detail that the investigation must examine.

After denying for days that it shot down the passenger plane, Iran's leaders apologized and admitted what they said was a mistake, striking a conciliatory tone.

That shifted on Wednesday when Iranian President Hassan Rouhani said European soldiers in the Middle East “could be in danger” as a result of Tuesday's decision by Britain, France and Germany to trigger a section of their 2015 nuclear agreement that could bring back European sanctions against Iran.

Prior to travelling to London, Champagne issued a statement supporting the European decision and called on Iran to “restore its full commitments” to the deal.

“Canada strongly supports the diplomatic engagement of France, Germany and the United Kingdom in pressing Iran to respect its commitments under the agreement,” Champagne said, noting that Canada is a “lead contributor” to the UN's International Atomic Energy Agency's role in monitoring Iran's compliance.

Garneau said the argument over the nuclear deal won't affect the countries whose representatives are meeting to talk about the crash.

The fate of the 2015 nuclear deal has been intertwined with the chain of events that led to last week's downing of the Ukrainian International Airlines plane by one, perhaps two Iranian surface-to-air missiles.

In 2018, President Donald Trump withdrew the United States from the deal - signed by the Obama administration, Germany and the five permanent members of the United Nations Security Council - designed to prevent Iran from enriching enough uranium to produce an atomic bomb. Trump started a campaign of “maximum pressure” to force Iran to renegotiate a better deal, but that hasn't happened.

On Jan. 3, Trump approved the drone attack that killed Iran's Maj.-Gen. Qassem Soleimani.

On Jan. 5, Iran said it would no longer abide by the nuclear deal's limits on the production of bomb-making material, but would still allow the UN to inspect nuclear facilities.

On Jan. 7, Iran retaliated for the Soleimani killing by firing missiles at two Iraqi military bases where American troops are based. Canadian military personnel were stationed at one of them.

A day later, the Ukraine passenger jet was shot down. In a Global News interview aired Monday, Prime Minister Justin Trudeau said had it not been for the recently elevated tensions, “those Canadians would be right now home with their families.”

On Tuesday, Iran announced arrests after “extensive investigations,” but has yet to offer further details about specific charges.

North Americans of Iranian descent say that while Iranian leaders appear to be taking unprecedented steps to soothe the pain of crash victims' loved ones, their true intentions are to maintain power.

They question whether Tehran is simply trying to tamp down the outrage of Iranian protesters that have taken to the streets in recent days after their government admitted - after its initial denials - that they shot down a plane carrying their fellow citizens.

“It is a massive crisis in Iran, and it's a question mark as to whether these arrests and these measures will be sufficient to satisfy the public who clearly view this as going far, far higher than just a couple of operatives who dealt with the anti-aircraft missiles,” said Trita Parsi, an Iranian-born analyst who co-founded the Quincy Institute for Responsible Statecraft in Washington.

Kiavash Najafi, an Iranian-born Canadian who served as an aide to the NDP's long-time and deceased foreign affairs critic Paul Dewar, said the Iranian regime is split between people who want to co-operate with the West, “and those who don't.”

As it prepares to meet allies in London, Najafi said Canada has an opportunity seek an additional form of justice that would also honour the legacy of the crash victims.

“It's not just seeking justice for the victim and their families, but also it's to keep creating conditions so the country (Iran) can move forward towards democracy. That's what the majority of Iranians want,” said the 36-year-old Najafi, who spent his first 16 years in Iran.

“Given that we have found this unique opportunity for Canada to have influence, I think it's really important to not lose sight of those aspects.”

This report by The Canadian Press was first published Jan. 15, 2020.