The United States, Russia, Saudi Arabia and Turkey failed to resolve key differences on political transition in Syria during meetings on Friday in the Austrian capital of Vienna.
However, the talks were still viewed as constructive and diplomats from the four nations are expected to meet again next week in an expanded format involving representatives from more countries, possibly including Iran, according to Reuters.
While new ideas were put forward, the countries remained deeply divided on the fate of President Bashar al-Assad, with the U.S. insisting he must relinquish power and Russia launching joint military operations with Assad last month and allegedly propping up his regime.
"I am convinced, having been part of this process since the day I became secretary that today's 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 changing the dynamic," U.S. Secretary of State John Kerry told reporters after the meeting, reported The Associated Press.
"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," Kerry added.
Kerry said it is still undecided whether Iran, another key ally of Assad, will be invited to participate in the next meeting.
In a separate development, Russian Foreign Minister Sergei Lavrov said Friday that Russia and Jordan have agreed to coordinate their military operations in Syria and will establish a coordination center to help integrate their air campaigns against the Islamic State group.
Lavrov said he invited the U.S., Saudi Arabia and Turkey to join the coordination center along with Jordan, who is a member of the U.S.-led coalition currently bombing the Islamic State group in Iraq and Syria, according to The Wall Street Journal.
The U.S. has so far refused to cooperate with Russia, other than to establish a basic agreement to prevent mid-air collisions.
