Vienna: The United States, Russia, Saudi Arabia and Turkey failed to resolve differences on the fate of Syrian President Bashar al-Assad in talks on Friday but could meet again in a week to discuss how to end Syria's civil war.
Speaking to reporters afterwards, ministers said they had been unable to bridge the central dispute between Washington and its allies, who say Assad has no future in Syria, and Russia, which showed its support by hosting him in Moscow this week.
In a separate development, Russia and Jordan agreed to coordinate their military actions on Syria by setting up a "special working mechanism" in the Jordanian capital, Amman, Russian Foreign Minister Sergei Lavrov said on Friday.
Russia's three-week-old campaign of air strikes against Islamist groups opposed to Assad has halted an offensive by rebels, including some backed by the United States and its allies, which had eroded Assad's control in the west of Syria.
Some diplomats and analysts believe Russia might be able to exploit its influence with Assad and its newly demonstrated military muscle in Syria's skies to broker a deal to end the conflict.
Speaking after the roughly two-hour meeting, US Secretary of State John Kerry acknowledged the fundamental disagreement but suggested that there may be a solution and spoke of the possibility of holding wider talks in a week's time.
"I am convinced that this meeting was constructive and productive and succeeded in surfacing some ideas, which I am not going to share today, but which I hope have a possibility of ultimately changing the dynamic," Kerry told reporters.
"What we agreed to do today is to consult with all parties and aim to reconvene, hopefully as early as next Friday, with a broader meeting in order to explore whether there is sufficient common ground to advance a meaningful political process."
He also pointedly did not exclude the possibility of bringing Iran, the Middle East's major Shi'ite Muslim power that backs Assad and is engaged in a regional power struggle with Sunni Muslim Saudi Arabia, into the discussions at some point.
"Diplomacy has a way of working through very difficult issues that seem to be absolutely contradictory and, on their face, begin at odds. And this is one of those issues where the statements clearly - and current positions - are at odds," Kerry said, noting that Russia and Iran have argued that Assad's presence is vital to the stability of Syria.
"But if we can get into a political process, then sometimes these things have a way of resolving themselves."
Kerry would not be drawn on whether, or when, Iran might be drawn into the process. "We want to be inclusive and err on the side of inclusivity rather than exclusivity," he said.
He added he was not opposed to the military agreement between Jordan, a close US ally, and Russia. "We have no problem whatsoever with this effort and it may even help make certain that the targets are the targets that they ought to be."
