Russia is hosting the Saudi foreign minister for Syria-focused talks, part of a new Moscow effort to mediate the conflict.

The talks Tuesday between Russian Foreign Minister Sergey Lavrov and his Saudi counterpart Adel Al-Jubeir follow their recent meeting in Doha that also involved U.S. Secretary of State John Kerry.

Moscow has been a key backer of Syrian President Bashar Assad, shielding his regime from U.N. sanctions and providing it with weapons throughout a civil war that has dragged on for more than four years. The conflict has left at least 250,000 dead and turned more than 4 million people into refugees.

While the Kremlin has shown no sign it could drop its support for Assad, its recent effort to engage the Saudis has reflected a shift in tactics.