The Russian Foreign ministry said Moscow would respond to a U.S. naval ship's entry into the Black Sea with unspecified measures, saying it and other deployments were designed to ratchet up tensions ahead of a NATO summit, the RIA news agency reported.

Russian state media reported that the USS Porter, a U.S. naval destroyer, entered the Black Sea a few days ago on a routine deployment, a move it said raised hackles in Moscow because it had recently been fitted with a new missile system.

U.S. Navy officials told reporters on Wednesday the U.S. military would also have two aircraft carriers in the Mediterranean this month ahead of a July NATO summit in Warsaw as Washington sought to balance Russian military activities.

He also said the deployment of U.S. aircraft carriers in the Mediterranean was a show of force which in his view deepened a chill in ties between Moscow and Washington caused by Russia's actions in Ukraine and Syria.

"As regards the overall situation of course there is a definite increase and stoking of tensions in our relations," he was quoted as saying.

"It is all being done on the eve of the Warsaw NATO summit. It is a show of force."