A Russian nuclear-powered submarine will visit Havana next week, Cuba's communist authorities said on June 6. The nuclear submarine Kazan, which will not be carrying nuclear weapons, and three other Russian naval vessels -- the missile frigate Admiral Gorshkov, an oil tanker, and a salvage tug -- will dock in the Cuban capital from June 12-17, Cuba's Revolutionary Armed Forces Ministry said. The unusual deployment of the powerful Russian submarine so close to the United States comes amid major tensions over the war in Ukraine. During the Cold War, the deployment of Soviet nuclear missile sites on the island triggered the 1962 Cuban Missile Crisis.