Russia's upper house of parliament has approved a request by President Vladimir Putin to deploy military forces abroad in Syria to aid the government of Bashar al-Assad in the fight against Islamic State militants.
A government spokesman said on state television that the vote regarded use of the Russian air force in Syria.
Russia has been building up its forces in Syria, with bombers, jets and troops arriving in northwest Syria in recent weeks, according to Pentagon officials.
On Monday, President Putin addressed the growing role of Russia in Syria, telling the United Nations General Assembly that the forces of Syrian President Assad are "valiantly fighting terrorism face to face" and that refusing to cooperate with them is "a huge mistake." He criticized the West for arming "moderate" rebels in Syria, who, he said, joined forces with the Islamic State group.