The Pentagon has said it regrets the death toll that was caused by airstrikes by US-led coalition jets on army positions near a military airport in Syria.

Russia said on Saturday that 62 Syrian forces lost their lives after warplanes from the international coalition led by the United States carried out four airstrikes against Syrian forces that were surrounded by ISIS in the Dayr al-Zawr air base.

"Sixty-two Syrian soldiers were killed and a hundred others were injured in these strikes," according to Russian army.

Also the US military's Central Command said in a statement on Saturday night that coalition forces thought they were attacking ISIS pisitions.

"If we did get this wrong, which it looks we did, it’s not something we intended to do," said a US military official, speaking on the condition of anonymity.

The official further described the incident as an "intelligence failure".

He went on to say that US forces followed the Syrian forces, thinking they were ISIS terrorists, adding that the militants appeared to have a tank and a number of other military vehicles.

The incident followed Moscow and Washington's deal on the Syrian crisis, when a truce went into effect on September 12.

The US-led coalition has failed to stop ISIS terrorists' advances in Syria and Iraq. Some political commentators have criticized the US-led military intervention, saying the strikes are only meant to benefit Washington and American weapons manufacturers.