Russia is fighting for Assad and has considerable sway over the various forces on the battlefield.

Pentagon spokesman Navy Captain Jeff Davis said any escalation in hostilities between the coalition and the pro-regime forces had been avoided thanks mainly to Russia’s influence.

“Russia has been very helpful and I think that the calm we see today is largely due to their efforts,” Davis said. “They are trying to get the other parties, the pro-regime, the Iranian-backed militias to do the right thing and to prevent them from taking actions that are destabilising.”

It was an unusual statement for the Pentagon, which in the past has roundly criticised Russian operations in Syria.

The Russian and US militaries have set up a special hotline to communicate about troop and plane movements over a crowded battle space, and the two sides regularly talk to avoid mishaps and ensure they are not operating in each others’ space.

Davis said there had been multiple military contacts over the At-Tanaf situation, both on the hotline and at “senior military levels.”

The Russians “have helped to pass messages and calm the situation there, and we hope that continues,” he said.

Tensions around the At-Tanaf garrison, where US and British commandos train local forces fighting the Islamic State group, have surged as pro-regime troops look to expand their influence.

Apart from the drone shoot down, the US has in recent weeks conducted three strikes against pro-regime forces it deemed to be threatening At-Tanaf.

But Davis said the coalition’s single goal was defeating IS and it sought to avoid getting drawn into the broader Syria conflict.

“We are only going to take action if we see things that they are doing that threaten us,” he said.

“Our only role there is to fight ISIS and that’s what we are doing.”