Russia put its military muscle on display, bringing Moscow-based reporters to view a day's worth of fighter jets roaring off a runway in dozens of sorties as helicopter gunships patrolled the edges of the sprawling facility.

Russian Foreign Minister Sergey Lavrov and U.S. Secretary of State John Kerry will meet Friday in Vienna, joined by their counterparts from Saudi Arabia and Turkey, both staunch critics of President Bashar Assad.

Lavrov said he wanted to provide "firsthand information" about the Russian air campaign against Islamic State militants in Syria, but also talk about a future political process in the country that is now in its fifth year of civil war.