US Secretary of State Rex Tillerson also said Russia had an obligation to prevent the use of chemical weapons by Bashar al Assad's regime.
The United States is prepared to work with Russia on establishing "no-fly zones" in Syria as part of a joint effort to stabilise the war-ravaged country, Secretary of State Rex Tillerson said on Wednesday, ahead of President Donald Trump's first face-to-face with Vladimir Putin.
In a wide-ranging statement, Tillerson said Russia had a "special responsibility" to help create stability on the ground – or risk hobbling the fight against Daesh.
Citing their past cooperation on the creation of de-escalation zones in Syria, Tillerson made a strong case for both countries – in spite of their "unresolved differences on a number of issues" – to work together in Syria.
"The United States is prepared to explore the possibility of establishing with Russia joint mechanisms for ensuring stability, including no-fly zones, on the ground ceasefire observers, and coordinated delivery of humanitarian assistance," he said.
TRT World spoke with journalist Harry Horton for the latest.
Tillerson issued his statement before joining Trump in Europe, where the US leader will meet Putin for the first time on Friday on the sidelines of a G20 summit in Hamburg, Germany. Syria will loom large in their discussions.
It also came as US-backed militants inch forwards in Raqqa's Old City, in what Washington sees as a "key milestone" in the campaign to defeat Daesh in its de facto Syrian capital.
"ISIS [Daesh] has been badly wounded and could be on the brink of complete defeat in Syria if all parties focus on this objective," Tillerson said. "In order to complete the mission, the international community, and especially Russia, must remove obstacles to the defeat of ISIS."
"We call upon all parties, including the Syrian government and its allies, Syrian opposition forces, and Coalition forces carrying out the battle to defeat ISIS, to avoid conflict with one another and adhere to agreed geographical boundaries for military de-confliction and protocols for de-escalation."
Russia, Turkey and Iran, without the US, agreed in May to establish four "de-escalation" zones in Syria. These are supposed to include no-fly areas, where no warplanes can fly so as to guarantee the safety of civilians on the ground.
But on Wednesday those countries said they had failed to agree on the details, such as the boundaries of the zones and who will police them.
Tillerson also said Moscow as a key backer of Syrian regime leader Bashar al Assad has the responsibility of preventing his forces from further use of chemical weapons.
The US launched a cruise missile attack on a Syrian air base in April in response to what it said was a government chemical weapons attack on civilians.