US Secretary of State John Kerry said he saw an opportunity for progress this week towards ending Syria's four-year civil war, as he met Iran's Foreign Minister Mohammad Javad Zarif on the sidelines of the UN General Assembly on Saturday.
Western officials said Kerry wants to launch a new initiative to find a political solution to the Syrian conflict, which has taken on a new urgency in light of Russia's military build-up in support of Syrian President Bashar al-Assad and a refugee crisis that has spilled over into Europe.