MOSCOW (Reuters) - Russia is sending two warships to the east Mediterranean, Interfax news agency said on Thursday, but Moscow denied this meant it was beefing up its naval force there as Western powers prepare for military action against Syria.

Russia's President Vladimir Putin (C) attends a conference at the main operation centre of the Russian armed forces, with Defence Minister Sergei Shoigu (L) and armed forces Chief-of-Staff Valery Gerasimov (R) in Moscow, June 6, 2013. REUTERS/Michael Klimentyev/RIA Novosti/Kremlin

Interfax quoted a source in the armed forces’ general staff as saying Russia, Syria’s most powerful ally, was deploying a missile cruiser from the Black Sea Fleet and a large anti-submarine ship from the Northern Fleet in the “coming days”.

Any strengthening of the navy’s presence could fuel tension, especially as the United States has said it is repositioning naval forces in the Mediterranean following an alleged chemical weapons attack which is blames on Syrian government forces.

“The well-known situation now in the eastern Mediterranean required us to make some adjustments to the naval force,” the source said in a reference to the events in Syria.

It was not clear when the vessels would arrive but Interfax said the Moskva missile cruiser was currently in the North Atlantic and would set sail in the next few days.

President Vladimir Putin has said the naval presence is needed to protect national security interests and is not a threat to any nation. Russia cooperates with NATO navies against piracy and its ships call at Western ports.

The navy later indicated a deployment was imminent in the Mediterranean but gave no details except to say it would be part of a long-planned rotation and suggested it would not increase the size of Russian forces there.

“This is not a new group ... but a planned rotation,” an highly-placed navy official who was not identified told state-run RIA news agency.

The reason for the discrepancy in the reports by Interfax and RIA was not clear but confusion has at times surrounded previous Russian deployments in the Mediterranean because of the secrecy involved. The Defence Ministry declined comment.

Washington accuses Syrian government forces of carrying out last week’s chemical weapons attack and has made clear it could soon launch a military strike.

Russia is one of Assad’s biggest arms suppliers. It opposes any military intervention in Syria and has shielded Damascus against further sanctions at the U.N. Security Council.

Defense experts said the deployment of the two warships identified by Interfax could give Assad early warning of cruise missile launches, particularly by submarine, or jam radars or navigation systems although they might never be used for this.

“What we may be seeing here is an example of gunboat diplomacy rather than a deliberate attempt to interfere directly in any coalition strike militarily,” said Lee Willett, editor of IHS Jane’s Navy International.

“The simple presence of any ships will have an impact politically, and that is the primary intent.”

Russia’s chief of staff said in June the navy had stationed 16 warships and three ship-based helicopters in the Mediterranean, its first permanent naval deployment there since Soviet times.