Russia is preparing to send two warships to the Syrian port of Tartus, where Moscow operates a strategic naval base, to ensure the safety of its nationals, the Interfax news agency reported Monday.
The report comes as Russian President Vladimir Putin was set to meet his US counterpart Barack Obama on the sidelines of the G20 summit in the Mexican resort of Los Cabos later Monday amid tensions over Syria clouding bilateral ties.
"Two major amphibious ships -- The Nikolai Filchenkov and The Tsezar Kunikov -- are preparing to be dispatched to Tartus outside of their schedule," the Russian news agency quoted an unidentified officer from the Russian naval headquarters as saying.
The two ships will carry a "large" group of marines, Interfax added. There was no official confirmation of the report from the navy or the defence ministry.
The Tsezar Kunikov can carry 150 landing troops and various armaments including tanks, while The Nikolai Filchenkov can carry up to 1,500 tonnes of cargo and equipment, the report said.
Interfax said that the ships could be used to evacuate Russian nationals.
"The crews of The Nikolai Filchenkov and The Tsezar Kunikov and SB-15 rescue tug together with marines on board are able to ensure security of Russian nationals and evacuate part of the property of the logistical support base if need be," Interfax quoted a source as saying.
The protracted conflict between the ruling regime and the opposition in Syria shows no signs of easing.
The opposition has demanded the deployment of armed peacekeepers after UN observers halted their work because of bloodshed.
Russia and its ally China have previously blocked earlier attempts at the UN Security Council to condemn Damascus and have shielded Assad's regime from further pressure amid accusations that Moscow has been sending weapons to Damascus.
United States Secretary of State Hillary Clinton has accused Russia of fuelling the violence by sending attack helicopters to Syria, which she said were "on the way" and would "escalate the conflict quite dramatically."
Russia angrily retorted that it was not making any new deliveries and had only carried out repairs of helicopters sent there many years ago.
Syria, one of the few countries to back Russia in its war with Georgia in 2008, is Moscow's close ally from the Soviet-era and a major purchaser of its arms.
Putin's predecessor at the Kremlin, Dmitry Medvedev, travelled to Damascus in 2010 in the first ever visit to the country by a Russian or Soviet head of state.
During talks with Assad he promised Russian assistance to Syria in reconstructing its oil and gas infrastructure and even in building a nuclear power station.
Over the past months the Kremlin has distanced itself from Assad but is sticking to its hard line, ruling out foreign intervention and insisting Assad's fate should be decided by Syrians themselves.