Flowers and candles are placed in front of the portraits of the flight crew members of the Ukraine International Airlines Boeing 737-800 plane that crashed in Iran, at a memorial at the Boryspil International Airport, outside Kiev, Ukraine, Jan. 8, 2020. Photo: Reuters / Valentyn Ogirenko / File.

Canada, Britain, Sweden and Ukraine on Thursday said they had abandoned efforts to talk to Tehran about reparations for an airliner downed by Iran and would try to settle the matter according to international law.

Most of the 176 people killed when Iran shot down the Ukrainian jet in January 2020 were citizens from those four countries, which created a coordination group that seeks to hold Tehran to account.

“Despite our best efforts over the past two years and multiple attempts to resolve this matter through negotiations, the Coordination Group has determined that further attempts to negotiate with Iran … are futile,” it said in a statement.

“The Coordination Group will now focus on subsequent actions to take to resolve this matter in accordance with international law,” it continued, but did not give details.

Tehran says Revolutionary Guards accidentally shot down the Boeing 737 jet and blamed a misaligned radar and an error by the air defense operator at a time when tensions were high between Tehran and the United States.

A court in Ontario, Canada, this week awarded C$107 million ($83.8 million), plus interest, to the families of six people who died. In June, Canada said it had found no evidence that the downing of the plane had been premeditated.