The US says Russia's claim that its warplanes flew a joint mission over Syria with the coalition against Isis is "rubbish".

Russia's Defence Ministry said today its forces in Syria had received coordinates of Isis (Islamic State) targets near al-Bab yesterday "from the US side via a hotline with the international coalition headquarters".

US Air Force Colonel John Dorrian, a coalition spokesman, almost immediately labelled the Russian claim as propaganda.

US Navy Captain Jeff Davis, a Pentagon spokesman, said the US does have routine "deconfliction" talks with Russia to avoid unintended aerial incidents in Syria's crowded skies.


But Davis says there have been no changes to that arrangement, and the US has insisted for months that it has no coordination or sharing of targets with Russia.

Russia pushed for such cooperation in the past, but Barack Obama's Administration had refused.

New President Donald Trump has called for joint efforts with Russia against Isis (Islamic State).

White House spokesman Sean Spicer said today that Trump is open to working with Moscow to fight Isis in Syria.

Meanwhile, in Astana, Kazakhstan, Russian-backed peace talks aimed at ending the Syrian war brought rebels and the Syrian Government face to face for the first time today, marking the launch of a new role for Russian President Vladimir Putin as a Middle East power broker.

The talks began with little fanfare and limited expectations after the collapse of other bids to end Syria's nearly six-year cycle of conflict and humanitarian misery.

One reason for hope this time is the evolving role of Russia, a critical political and military backer of Syrian President Bashar Assad. In the past, Moscow had frequently acted as a spoiler when the United States was driving the diplomacy on Syria, but is now embracing a role as mediator between Assad's government and moderate rebels Russian officials once denounced as terrorists.

Turkey and Iran are co-sponsors of the talks, but it is Moscow that has thrown its prestige behind the effort to bring the warring factions together, leaving little doubt that this is a Russian-led process, diplomats said. The US has been relegated to observer status, and has not been a party to the intensive negotiations preceding the talks.

In one early success for Moscow's diplomacy, representatives for Assad and the Syrian rebels seeking to overthrow him sat together in the same room for the opening session of the talks - the first time they have encountered one another directly since the bloodshed began in 2011.

Participants described the mood as frosty as the warring factions took their places on opposite sides of a conference room in Astana's deluxe Rixos Hotel, a Turkish-owned chain. Between them were representatives of Russia, Turkey and Iran, and the UN's top Syria envoy, Staffan De Mistura. The US ambassador to Kazakhstan, George Krol, attended as an observer.

In one sign that expectations for meaningful progress are low, there are no plans for direct negotiations between the two sides. For subsequent meetings, the rival delegations will meet in separate rooms, with envoys of the United Nations and the sponsoring powers shuttling between them.

- additional reporting AP