A group of countries led by Canada on Wednesday called for an arbitrator to settle claims against Iran over its shooting down of a Ukrainian passenger plane in January 2020.
The move is a first step in possibly bringing a case against Iran at the International Court of Justice, which victims' families have long demanded.
"Those who lost loved ones in the downing of PS752 deserve justice," Canadian Foreign Minister Melanie Joly tweeted.
"We have taken an important step to advance our pursuit of that justice at the international level this week and will continue to work together to hold Iran accountable for this tragedy."
Iranian forces shot down Ukraine International Airlines flight PS752 shortly after its take-off from Tehran on January 8, 2020, killing all 176 people aboard, including 85 Canadian citizens and permanent residents.
Three days later, Iran admitted that its military had targeted the Kyiv-bound Boeing 737-800 plane by mistake.
Canada, Britain, Sweden and Ukraine have been seeking reparations on behalf of the victims' families.
They said in a joint statement Wednesday that they "have requested that Iran submits to binding arbitration of the dispute related to the downing of Flight PS752," under a 1971 multilateral treaty on threats to civil aviation.
And if the parties cannot agree within six months on the terms for organizing an independent arbitration tribunal, the dispute may be referred to the International Court of Justice in The Hague.
Hamed Esmaeilion, a spokesman for the victims' families, said in an online video they have long waited for the Islamic regime to be held to account for the air disaster and provide "every minute detail of the truth" about what happened.
"The association of families of Flight PS752 have endured great hardship to reach this important and essential milestone on the path to justice that was marred by legal and political twists and turns," he said.
The group of countries led by Canada accuses Iran's Islamic Revolutionary Guard Corps of having "launched unlawfully and intentionally" two surface-to-air missiles at the jetliner.
The Iranian Civil Aviation Organization has pointed in a report to the alertness of its troops on the ground, who shot the missiles amid heightened tensions between Iran and the United States at the time.
Ukraine, which lost 11 citizens in the disaster, has said the report was "a cynical attempt to hide (the) true causes" of the tragedy, while Canada said it contained "no hard facts or evidence."
