A dispute over the future of Syrian President Bashar al-Assad sparked tensions at the conference, with the U.S. saying there was no way he could stay in power, while Syria balked at such an assertion. SANA/Handout via Reuters

Talks in Switzerland aimed at carving a path out of Syria's civil war got off to a rocky start Wednesday as a bitter clash over President Bashar al-Assad's future threatened to collapse the negotiations.

Fighting raged in Syria even as diplomats sparred against a pristine Alpine backdrop in Montreux, with government forces and opposition fighters clashing across a wide area from Aleppo and Idlib in the north to Daraa in the south, according to activists and state media.

Just hours into the first day of talks, which are the beginning of a process designed to map out a transitional government and ultimately a democratic election, the government and opposition seemed impossibly far apart.

"There will be no transfer of power, and President Bashar Assad is staying," Information Minister Omran al-Zoubi told reporters.

Ahmad al-Jarba of the western-backed Syrian National Council (SNC) had wavered up to the last minute on whether to attend the peace talks, which have largely been opposed by rebel brigades in Syria. He said any discussion of Assad's continued hold on power would effectively end the talks.

A transitional government "is the only topic for us," he said.