Russian President Vladimir Putin said Thursday that Moscow's goal in Syria was to “stabilise the legitimate authority” and strike a “decisive blow” against terrorism.

“We have no plans to interfere in Syria's internal affairs,” he told a group of naval officers returning from Syria, where six years of war have killed more than 310,000 people.

“Our task is to stabilise the legitimate authority in the country and strike a decisive blow against international terrorism,” said Putin, whose administration is a key ally of the government of President Bashar al-Assad.

Putin's comments, broadcast on Russian television, came as UN-backed peace talks were opening in Geneva between opposition and government delegations.

“The sooner the country reaches a political settlement, the better the chances for the international community to put an end to the terrorist plague on Syrian territory,” he said.

Russia began its military intervention to bolster Assad's forces in September 2015, turning the tables on the battlefield just as militant forces were strengthening their hold on key areas.

Russian intervention also helped the Syrian government retake militant areas in the east of the northern city of Aleppo after four years of fighting.

In January, Moscow withdrew its naval force from Syrian waters, including its only aircraft carrier in service, the Admiral Kuznetsov, as part of an announced reduction of its military role.

Putin said the naval force had fulfilled its objective of helping to “create the conditions for pursuing peace talks between the Syrian government and the armed opposition.”

He also said that Russia's Syria intervention had “contributed directly to Russia's security”.

According to Russian intelligence services, about 4,000 Russian citizens and 5,000 citizens from the former Soviet Union are fighting alongside the militant Islamic State group in Syria, Putin said, posing an “enormous risk” for Russia.