The threat of direct Russian-American confrontation in Syria escalated on Monday after Moscow said it would treat any plane from the US-led coalition flying west of the Euphrates river as a potential target.

Russia said it was responding to US planes shooting down a Syrian air force jet on Sunday. The US said its planes had acted to defend US-backed forces seeking to capture the Islamic State capital of Raqqa in north-east Syria.

It was the first such US attack on a Syrian warplane since the start of the country’s civil war six years ago.

Russia’s deputy foreign minister, Sergei Ryabkov, said the US strike “has to be seen as a continuation of America’s line to disregard the norms of international law.

“What is this if not an act of aggression? It is, if you like, help to those terrorists that the US is fighting against, declaring they are carrying out an anti-terrorism policy.”

The Russian foreign ministry also said it would respond to the attack by suspending its communications channel with US forces, which is designed to prevent collisions and dangerous incidents in Syrian airspace.

The top US general, Joseph Dunford, sought to play down the repercussions of the incident, insisting the hotline established eight months ago between US central command in Qatar and its Russian equivalent in Syria was still open and functioning on Monday morning and would be used to try to defuse the situation.

“I’m confident that we are still communicating between the coalition operations centre and the Russian operations centre,” Dunford, chairman of the joint chiefs of staff told the National Press Club in Washington. “I think the worst thing any of us could do would be to address this with hyperbole.”

He added: “I’m also confident that our forces have the capability to take care of themselves.”

The Russian military threatened to close the hotline, known as the “deconfliction channel”, in April after President Trump ordered a missile strike against a Syrian air base allegedly involved in a chemical weapons attack. However, Moscow did not fulfill the threat and the channel remained open.

The prime minister, Theresa May, intervened on Monday, urging Russia not to end the “deconfliction arrangements” since it would increase the risk of an air fight breaking out inadvertently between Russian and US-led coalition warplanes.

The growing risk of a direct confrontation between the US and Russia follows a decision by Trump to grant his military chiefs untrammelled control of military strategy in Syria.

But the Pentagon insisted it was not seeking to escalate the conflict and had acted only after the Syrian jet in question had dropped bombs near US partner forces involved in the fight to wrest Raqqa from Isis control.

“It’s important to point out that the incident that took place this weekend followed a combined arms movement by pro-regime forces. Subsequently, an SU [Russian-made Syrian regime] aircraft flew into the area,” Dunford said.

“We made every effort to warn those individuals not to come any closer and then the commander made a judgment that it was a threat to the forces that we are supporting and took action. The only actions that we have taken against pro-regime forces in Syria, and there have been two specific incidents, have been in self-defence and we have communicated that clearly.”

It is not clear what other incident Dunford was referring to. Apart from the April missile strike, US forces have fired on pro-regime forces, thought to include Iranian-backed Shia militia, three times in the past month in Syria’s eastern desert near the Iraqi border.

Asked about the legal basis for a US plane shooting down a Syrian aircraft in Syrian airspace, Dunford referred to the Authorisation for the Use of Military Force Act passed by Congress in 2001 in the wake of the 9/11 attack, which has been used as a blanket mandate by US administrations ever since for counter-terrorist operations abroad.

US Gen Joseph Dunford: ‘We made every effort to warn those individuals not to come any closer.’ Photograph: Aaron P Bernstein/Reuters

White House spokesman Sean Spicer, speaking later, said that the US would “do what we can” to keep military communications channels open in Syria.

“While we want to de-escalate the situation there ... we will always preserve the right to self-defence,” Spicer added.

Russia stressed it will in future be tracking the coalition’s jets, not shooting them down, but added that “a threat for those jets may appear only if they take action that poses a threat to Russian aircraft”. Moscow’s foreign ministry said in a statement: “All kinds of airborne vehicles, including aircraft and UAVs [unmanned aerial vehicles] of the international coalition, detected to the west of the Euphrates river will be tracked by the Russian SAM systems as air targets.”



The US military confirmed that a US Navy F/A-18 Super Hornet shot down a Syrian SU-22 on Sunday. The US said the Syrian jet had dropped bombs near Syrian Democratic Forces (SDF) fighters who are aligned with US forces in the fight against Isis. Damascus said its plane had been on anti-Isis mission.

Col John Thomas, a spokesman for US Central Command, said there were no US forces in the immediate vicinity but that the SDF was under threat for more than two hours.

The SDF, an alliance of Kurdish and Arab fighters working alongside western special forces, said it would take action to defend itself from Syrian warplanes if attacks continued.



The Trump administration has promised to improve arms supplies to the SDF after it concluded that it was the force most capable of freeing Raqqa from Isis.

Growing tensions between Washington and Moscow over efforts to dislodge Isis from its Raqqa stronghold are a long way from Trump’s original plan to work with Russia in Syria to defeat the terror group.

Russia, a staunch supporter of Syria’s president, Bashar al-Assad, had been pressing the US to make the removal of Isis a joint land and air operation, but discussions over Syria’s long-term political future appear to have ground to a halt, leaving the US military to operate in a political vacuum.

Senior US lawmakers have been voicing concern at the lack of a declared Trump administration strategy for Syria beyond the crushing of Isis. Democratic senator Chris Murphy warned on Twitter: “Four direct engagements with Syria/Iran/Russia in 45 days. Trump is quietly starting a new war that Congress has not declared. Red alert.”

In a sign of how complex the Syrian peace process has become, Russian-sponsored peace talks in Astana, Kazakhstan, are scheduled to resume on the same day – 10 July – as talks convened by the UN in Geneva.

The Russian foreign minister, Sergei Lavrov, announced the date on Monday in the knowledge that it would coincide with the UN schedule. He also said that the UN’s Syria envoy, Staffan de Mistura, would take part.

A spokesman for de Mistura said “the subject is currently being discussed”.