The UN’s special envoy for Syria Geir Pedersen on Friday urged Russia to help stabilize the violence in northwestern Idlib province and support drafting the nation’s new constitution. During talks with Russian Foreign Minister Sergey Lavrov in Moscow, Pedersen voiced hope that Moscow and Ankara could help reduce tensions in Idlib, AP reports.

“It’s a very difficult situation,” the envoy said. “I hope that the cooperation between Russia and Turkey will help to stabilize the situation in Idlib.”

Russia and Turkey have closely coordinated their actions in Syria, signing a de-escalation deal for Idlib. The province is the last major rebel stronghold in Syria’s eight-year civil war.

Pedersen will travel to Syria early next week for talks on forming a constitutional committee.