The Russians have said any weapons and personnel on board the ship are for reinforcement of the Tartous facility.

CNN: Annan: Iran has 'role to play' for Syrian peace

Two Russian military transport ships were scheduled to transit through the Dardenelles Strait Tuesday, on their way to their expected destination, the Syrian port of Tartous, a U.S. official said.

CNN: Annan: Iran has 'role to play' for Syrian peace

And U.S. officials said they were aware of reports that Russia may be preparing to send ships and military personnel to help secure a Russian naval base at the Syrian city of Tartous.

WSJ: Rival Powers Hit Wall on Syria Plan