Syria's main opposition group said it would attend peace talks on Monday but accused the government of President Bashar al-Assad of preparing to escalate the war.
The Syrian army secured a major battlefield victory Wednesday as Russia vowed no let-up in its aerial bombardment in support of the regime, putting further pressure on fragile peace efforts in Switzerland.
Syrian opposition chief Riad Hijab arrived in Switzerland on Wednesday afternoon, his grouping said, in a move that could rekindle troubled UN-brokered peace talks.
US Secretary of State John Kerry said he hoped for "clarity" within 48 hours on talks aimed at ending Syria's five-year war which had been due to start Monday.
