U.S. Secretary of State John Kerry and Russian Foreign Minister Sergei Lavrov returned to Syria talks on Saturday, three weeks after the failure of their painstakingly drafted ceasefire that many saw as the last hope for peace this year.
Kerry has pointedly avoided new bilateral negotiations with Lavrov, and his invitation to the Turkish, Saudi, Qatari, Iranian, Jordanian and Egyptian foreign ministers to join them for talks in the Swiss lakeside town of Lausanne will broaden the discussion to include powerful backers of Syria's government and rebels.
"We've asked countries to come, having done some thinking, about a realistic way forward given the differences represented in the room," a senior U.S. State Department official said.
Since the breakdown of U.S.-Russia cooperation, long the backbone of efforts to end the war in Syria, U.S. officials have worked through ideas, some of which will be presented in Lausanne, the official said.
"With all that said, I'm not expecting we will have some major announcement at the end of this. This is going to be, as it has been now for several years, a very difficult process," the official added.
The new talks will not deliver an immediate solution, but could be the basis of a new process, the official said.
Pressure is rising for a halt to a ferocious, three-week-old Syrian government offensive to capture the rebel-held eastern zone of the city of Aleppo, where the United Nations says 275,000 civilians still live and 8,000 rebels are holding out against Syrian, Russian and Iranian-backed forces.
Western powers have accused Russia and Syria of committing atrocities by bombing hospitals, killing civilians and preventing medical evacuations, as well as targeting an aid convoy with the loss of around 20 lives.
Syria and Russia counter that they only targeting militants in Aleppo and accuse the United States of breaking the ceasefire by bombing scores of Syrian troops fighting Islamic State insurgents, over which the United States has expressed "regret".
A senior rebel commander said on Friday Syrian government forces would never be able to capture Aleppo's eastern sector, but a military source said the operation was going as planned.
The United Nations has said food, fuel and medicine are running out in eastern Aleppo and there will be no rations to distribute from the start of next month.
In a gesture of apparent desperation, U.N. Syria peace envoy Staffan de Mistura has offered to escort members of an Islamist militant group, Jabhat Fateh al-Sham, out of Aleppo if that would entice Damascus to forge a ceasefire with the remaining rebels.
Lavrov has said he does not plan to bring new proposals to Lausanne.
But his deputy Gennady Gatilov said Russia wants to discuss de Mistura's offer, as well as elements of last month's failed truce deal, namely humanitarian aid deliveries and a pullout of both sides' troops from the Castello Road, a key supply route.
"And it's about time to start moving toward an inclusive political process," Gatilov told Interfax news agency.
Many in Syria's opposition say Kerry has put too much trust in Lavrov, with protracted diplomatic wrangling over ceasefires buying time for Russia's military campaign and obscuring the once central question of the fate of Syrian President Bashar al-Assad, while the clock runs down to the U.S. elections on Nov. 8.