The US and Russia have agreed to hold a third round of military talks over the ongoing aerial campaign in Syria after rival jets came within sighting distance of one another. Two Russian and two American aircraft were separated by just 10 to 20 miles, putting the spotlight on the crowded Syrian airspace.

Even though the episode caused no incident, Washington termed Moscow's actions "reckless" and irresponsible". Colonel Steve Warren, spokesperson for the US-led coalition pounding Islamic State (Isis) targets in Iraq and Syria, said Russia's manned aircraft continue to shadow US drones operating in the region, and often break aerial protocol. "Everyone went about their business" subsequent to the aerial encounter, Warren added.

Russia has not commented on the incident. The renewed talks are an attempt to de-escalate such cases in the future. Speaking from Boston, US Secretary of Defence Ash Carter said: "Russia must act professionally in the skies over Syria and abide by basic safety procedures. We'll have another conversation with the Russians tomorrow on this subject. Those discussions are progressing. Nothing has been finalised."

Carter admitted the military-to-military discussions may not alter the two countries' approach in Syria but sought safety in the skies. "Even as we continue to disagree on Syria policy, we should be able to at least agree on making sure our airmen are as safe as possible," he said.

Washington holds on to its position that Syrian President Bashar al-Assad must be removed from power while Russia insists on a role for him in the war-torn country's future. Since beginning the airstrikes on 30 September, Russia has dramatically stepped up its military campaign in Syria which, the West argues, has further empowered Assad's regime.