US coalition partners Australia and Denmark expressed remorse on Monday for a weekend airstrike against Islamic State militants in eastern Syria that killed scores of Syrian soldiers and has pushed US-Russian relations to breaking point.
Australian Prime Minister Malcolm Turnbull told reporters that the Saturday operation targeting Islamic State militants in the eastern Syrian province of Deir al-Zour ended as soon as coalition commanders were told by Russia that Syrian forces were affected.
"We regret the loss of life and injury to any Syrian personnel affected," Turnbull said in New York, where he is visiting for the annual United Nations General Assembly.
The airstrike killed 90 Syrian regime troops, according to the Syrian Observatory for Human Rights. Russia said on Sunday the strikes were "on the edge between a criminal negligence and direct indulging of IS [Islamic State] terrorists."
Australian Defence Minister Marise Payne told Australian broadcaster ABC on Monday that Australia is taking part in a US review of the airstrikes.
Denmark was also participating in the investigation after the country's Defence Command admitted late Sunday that two Danish F-16 jet fighters were deployed in Saturday's coalition raid.
"It is deeply regrettable if the [US-led] coalition attacked a Syrian military position due to an error," Defence Minister Peter Christensen said in a statement to Danish news agency Ritzau.
The airstrike has cast doubts over a ceasefire, brokered by Washington and Moscow, that took effect last week with the aim of halting the multi-sided conflict in Syria and relaunching a UN-sponsored peace process.