Russian President Vladimir Putin has called for a regional "co-ordinating structure" against jihadist militant group Islamic State (IS).
Mr Putin reiterated his support for Syrian President Bashar al-Assad, who Western countries and the Syrian opposition have said must go.
The crisis is expected to be high on the agenda at the UN in New York.
Mr Putin will hold rare talks with US President Barack Obama to discuss the issue later on Monday.
Relations between Russia and the West have been strained over Moscow's annexation of Ukraine's Crimea peninsula last year and support for separatist rebels.