A Russian document circulating at the United Nations has proposed a constitutional reform process in Syria, lasting 18 months, to be followed by presidential elections.
The document does not say whether Syrian President Bashar al-Assad should remain in power during that time, but says certain Syrian opposition groups should take part in key talks on the crisis in Vienna on Saturday.
The Syrian army meanwhile has broken a siege at the Kuwairis airbase, east of Aleppo, and eliminated large numbers of Islamic State militants.
The facility had been under attack by IS jihadists for nearly two years.
It represents a victory for regime forces which have struggled to advance even since Russia added its firepower to the conflict at the end of September, flying hundreds of sorties in that time.
