UPDATE 3 - US regrets deadly airstrike on Syria regime forces

UPDATES TO ADD AUSTRALIAN STATEMENT

NEW YORK/WASHINGTON (AA) – If the United States mistakenly struck Syrian government troops in an airstrike, "we regret doing so, especially the loss of lives”, a U.S. official told Anadolu Agency on Saturday.

"The coalition aircraft conducting the mission believed they were striking ISIL forces near Dayr Az Zawr," Pentagon spokesman Peter Cook said in a statement sent to Anadolu Agency, using the department’s preferred spelling for Deir ez-Zour. He added that the U.S. continues to gather information about the strike inside Syria that drew Russian and Syrian outrage.

At least 62 Syrian forces died and almost 100 others were injured earlier in the day during an anti-Daesh coalition attack on a military base in eastern Syria, the Russian Defense Ministry said earlier in the day.

Following a UN Security Council meeting that the Russian mission to the UN called regarding the deadly airstrike, U.S. Ambassador to the UN Samantha Power accused Russia of pulling a "stunt" by calling the meeting.

"Even by Russia's standards tonight's stunt, a stunt replete with moralism and grandstanding, is uniquely cynical and hypocritical,” Power told reporters.

Power’s remarks came after the Russian ambassador to the UN reportedly condemned the airstrike during the closed meeting.

The air operation was carried out near Deir ez-Zour airport using two F-16 and two A-10 aircraft belonging to coalition forces, according to a statement issued by the Russian Defense Ministry's Facebook account.

The Pentagon said coalition aircraft conducted an airstrike south of Deir ez-Zour that was “halted immediately” after Russia informed the U.S.-led coalition “that it was possible the personnel and vehicles targeted were part of the Syrian military.

“Coalition forces believed they were striking a Daesh fighting position that they had been tracking for a significant amount of time before the strike,” Central Command said in a statement.

Australia’s Defense Department confirmed that some of the country’s aircraft were among those participating in the coalition operation.

“While Syria remains a dynamic and complex operating environment, Australia would never intentionally target a known Syrian military unit or actively support Daesh,” it said in a statement.

The department offered its condolences to the families of any Syrian personnel killed or wounded in the incident.

The crisis comes in the wake of a Russia-U.S. brokered week-long humanitarian cease-fire, and just days before the UN General Assembly gathers more than 190 world leaders for its annual summit.

The U.S. and Russia have also agreed to create a joint operations center to carry out strikes against the Nusra Front if the agreement holds for seven consecutive days.

It's unclear how, if at all, the strike Saturday would affect the proposal.