"We currently have no reason to believe this move is anything out of the ordinary but we refer you to the Russian government for more details," said Erin Pelton, a spokeswoman for the US National Security Council, on Tuesday.

The remarks came after reports said Russia has dispatched a naval flotilla, including two destroyers and three amphibious landing vessels, to the Syrian port.

Turkey's media said on Wednesday that the vessels have entered the Aegean Sea after passing through the Turkish strait of Dardanelles.

Russia's Interfax news agency quoted a military source as saying that the ships' mission had nothing to do with the ongoing unrest in the Middle Eastern country.

"The ships were carrying marines on a training mission as well as food, water and fuel for Russia's naval maintenance and repair base in Syria's Mediterranean port of Tartous," the source said on condition of anonymity.

Tartous is the place of Russia's sole naval base outside the former Soviet Union and Moscow dispatches its warships there regularly.