Russian President Vladimir Putin was given a formal consent by the country's parliament to deploy troops in Syria to aid its leader Bashar al Assad's forces in fighting the Isis militants.
Russia will deploy its air force to Syria on the request of Syrian president, Russian media reported on Wednesday.
Assad has already sought 'military aid' from Russia, AFP reported.
Putin had asked the parliament to authorise the deployment of Russian troops abroad, a step necessary as per the constitution.
"The Federation Council unanimously supported the president's request - 162 votes in favor [of granting permission]," Kremlin Chief of Staff Sergey Ivanov was quoted as saying by Russian news agency TASS.
According to reports, the Russian parliament took the decision to authorise troops to fight Isis militants in view of the increasing number of Russians joining the Islamic State over the past year.
Russia has intensified its military presence in the war-torn nation over recent weeks, even training Syrian forces in use of advanced weapons, much to the chagrin of the United States.
The Syrian issue was a major thorn during Putin's meeting with US President Barack Obama in New York on the sidlelines of the UN General Assembly recently. The differences over Assad remained even after the discussions, as per reports.