The Russian parliament has voted to extend Russia's lease of a naval base in Syria for 49 years following the announcement of a partial pullout of Russian troops from that country.

Russia's air campaign in Syria, which began in 2015, helped turn the tide of the Syrian civil war in favor of Moscow's long-time ally Bashar Assad. President Vladimir Putin earlier this month ordered a partial withdrawal from Syria but said Russia would keep its military presence there.

The State Duma on Thursday voted to ratify an agreement with Syria, submitted by Putin, for Russia to keep its warships at the Mediterranean base in Tartus for 49 years. The agreement allows Russia to keep 11 vessels there at a time including nuclear-powered ships.

Russia also operates an air base in Syria.