Russia has expressed concern about a U.S. warship just off its shores in the Black Sea.
The guided-missile cruiser USS Monterey is taking part in annual joint military exercises conducted by NATO and Ukraine.
Russia's Foreign Ministry issued a statement Sunday saying Moscow has repeatedly stressed that any elements of the U.S. strategic infrastructure in the immediate vicinity of Russia will be considered a security threat.
The statement comes after Russia and the West failed last week to reach an agreement on a missile shield project for Europe.
Russia Concerned About US Navy Vessel in Black Sea
