"According to our information, NATO ships are in the Black Sea and their numbers are increasing," said Vice Adm. Sergei Menyailo, commander of the Novorossiisk naval base.
He said some of the ships were at the port of Batumi in southwest Georgia. "We are monitoring the situation," he added.
Russia is concerned that NATO is continuing to build up its forces in the Black Sea. The military alliance announced its decision to deliver humanitarian aid to Georgia after the conclusion of hostilities between Tbilisi and Moscow over breakaway South Ossetia on August 12. Moscow recognized both South Ossetia and Abkhazia, another breakaway Georgia republic, on Tuesday, despite warnings by Western leaders not to do so.
Moscow has questioned why the U.S. military is needed to deliver aid to Georgia. According to a Russian military intelligence source, the NATO warships that have entered the Black Sea are carrying over 100 Tomahawk cruise missiles and Harpoon anti-ship missiles between them.
A U.S. Embassy spokesman said on Wednesday that a warship that was due to deliver aid to the Georgian port of Poti, where Russian troops have been carrying out patrols, would dock at Batumi. He did not explain the reason for the decision.
Menyailo said that the Moskva missile cruiser, the flagship of Russia's Black Sea Fleet, was approaching the port of Sukhumi, Abkhazia's capital.
According to Anatoly Nogovitsyn, the deputy chief of the Russian General Staff, the cruiser should have returned to its base in Sevastopol on Tuesday night.
Menyailo also said that the Russian naval group patrolling the waters off Abkhazia was sufficient to maintain peace and stability in the region. "We are not planning to increase the number of our ships there, but everything depends on regional stability,' Menyailo said.
He said the ships differed in kind, ranging from landing vessels to missile ships and submarine chasers.
"We are controlling territorial waters and the adjacent area, ensuring shipping safety, and preventing the smuggling of arms and military vehicles," the official said.
Russia's General Staff said on Tuesday there were ten NATO ships in the Black Sea - three U.S. warships, the Polish frigate General Pulaski, the German frigate FGS Lubeck, and the Spanish navy ship Admiral Juan de Borbon, as well as four Turkish vessels.