Russian forces have `` complete operational control '' of Crimea , a U.S. official says . By Sunday night , electricity had been cut off at the headquarters of the Ukrainian Navy in Crimea , and officials feared there could soon be an attack , Seleznyov said . The United States has not yet formally recognized the referendum as legitimate and is considering sanctions against those responsible for its annexation. Ukrainian PM says Russian actions are `` a declaration of war '' G7 leaders condemn Russia 's `` clear violation '' of Ukraine 's sovereignty .
Russian forces have `` complete operational control '' of Crimea , a U.S. official says . The United States has not yet formally recognized the referendum as legitimate and is considering sanctions against those responsible for its annexation. Ukrainian PM says Russian actions are `` a declaration of war '' G7 leaders condemn Russia 's `` clear violation '' of Ukraine 's sovereignty .