WarSclerotic

MOSCOW — Russia said on Tuesday that it had dispatched a flotilla of 11 warships to the eastern Mediterranean, some of which would dock in Syria. It would be the largest display of Russian military power in the region since the Syrian conflict began almost 17 months ago. Nearly half of the ships were capable of carrying hundreds of marines.

The announcement appeared intended to punctuate Russia’s effort to position itself as an increasingly decisive broker in resolving the antigovernment uprising in Syria, Russia’s last ally in the Middle East and home to Tartus, its only foreign military base outside the former Soviet Union. The announcement also came a day after Russia said it was halting new shipments of weapons to the Syrian military until the conflict settled down.

Russia has occasionally sent naval vessels on maneuvers in the eastern Mediterranean, and it dispatched an aircraft-carrying battleship, the Admiral Kuznetsov, there for maneuvers with a few other vessels from December 2011 to February 2012. There were rumors in recent weeks that the Russians planned to deploy another naval force near Syria.

But the unusually large size of the force announced on Tuesday was considered a message, not just to the region but also to the United States and other nations supporting the rebels now trying to depose Syria’s president, Bashar al-Assad.

Tartus consists of little more than a floating refueling station and some small barracks. But any strengthened Russian presence there could forestall Western military intervention in Syria.

The Russian announcement got a muted response in Washington. “Russia maintains a naval supply and maintenance base in the Syrian port of Tartus,” said Tommy Vietor, a spokesman for the National Security Council. “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.”

The announcement came as a delegation of Syrian opposition figures was visiting Moscow to gauge if Russia would accept a political transition in Syria that excludes Mr. Assad. It also coincided with a flurry of diplomacy by Kofi Annan, the special Syria envoy from the United Nations and the Arab League, who said Mr. Assad had suggested a new approach for salvaging Mr. Annan’s sidelined peace plan during their meeting on Monday in Damascus.

While the Kremlin has repeatedly opposed foreign military intervention in Syria, Russian military officials have hinted at a possible role in Syria for their naval power. The ships have been presented as a means either to evacuate Russian citizens or to secure the fueling station at Tartus.

A statement by the Defense Ministry said ships had embarked from ports of three fleets: those of the Northern, the Baltic Sea and the Black Sea, and would meet for training exercises in the Mediterranean and Black Seas. Taking part, the statement said, would be two Black Sea Fleet landing craft that can carry marines: the Nikolai Filchenkov and the Tsezar Kunikov.

Russia’s Interfax news agency cited an unnamed military official as saying that an escort ship, the Smetlivy, would stop in Tartus for resupplying in three days — though it had presumably recently left its home port of Sevastopol, in the Black Sea.

Another contingent, from the Arctic Ocean base of Severomorsk, in the Murmansk Fjord, will take longer to arrive. That convoy includes three landing craft with marines escorted by an antisubmarine ship, the Admiral Chabanenko.

The voyage to the Mediterranean was unrelated to the Syrian conflict, the official said, but the boats laden with marines would stop in Tartus to “stock up on fuel, water and food.”

Visits on Tuesday by Mr. Annan to Iran, the Syrian government’s most important regional ally, and Iraq, Syria’s neighbor to the east, which fears a sectarian spillover from the conflict, came as a deadline of July 20 approaches. That is when the United Nations Security Council is to decide whether to renew the mission of 300 observers in Syria charged with monitoring the introduction of Mr. Annan’s peace plan. The observers’ work was suspended nearly a month ago because it was too dangerous.

At a news conference in Tehran, Mr. Annan reiterated his view that the Iranians had a role to play in resolving the conflict, despite objections from the United States. Mr. Annan also said Mr. Assad had proposed altering the peace proposal so that the most violent areas of the country would be pacified first. The current plan calls for an immediate cessation of all violence everywhere as a first step.

“He made a suggestion of building an approach from the ground up in some of the districts where we have extreme violence — to try and contain the violence in these districts and, step by step, build up and end the violence across the country,” Mr. Annan told reporters in Tehran.

There was no immediate word on whether the suggested new approach would be accepted by Mr. Assad’s opponents. But in Moscow, a delegation from the Syrian National Council, the umbrella opposition group in exile, suggested they had no interest in engaging with him.

“What brings together the opposition today is our consensus on the need to topple Assad’s regime and build a new political system,” Bassma Kodmani, a member of the delegation, said at a news conference in Moscow.

The delegation members, who are to meet on Wednesday with Foreign Minister Sergey V. Lavrov, also said they would not ask that Russia grant Mr. Assad asylum — something Russian officials have said they are not considering anyway.