Russian naval infantry soldiers (marines) guard the Orsk Russian landing ship anchored in the Ukraine's Black Sea port of Sevastopol on March 2, 2014. In 2010, after years of tortuous negotiations, Ukraine agreed to extend Moscow's lease on Sevastopol port until 2042 in exchange for a 30-percent reduction in the price of Russian gas on which Ukraine depends for much of its energy needs. AFP PHOTO / VIKTOR DRACHEV

Russian naval infantry soldiers (marines) guard the Orsk Russian landing ship anchored in the Ukraine's Black Sea port of Sevastopol on March 2, 2014. In 2010, after years of tortuous negotiations, Ukraine agreed to extend Moscow's lease on Sevastopol port until 2042 in exchange for a 30-percent reduction in the price of Russian gas on which Ukraine depends for much of its energy needs. AFP PHOTO / VIKTOR DRACHEV

Russian naval infantry soldiers (marines) walk as they guard the Orsk Russian landing ship anchored in the Ukraine's Black Sea port of Sevastopol on March 2, 2014. In 2010, after years of tortuous negotiations, Ukraine agreed to extend Moscow's lease on Sevastopol port until 2042 in exchange for a 30-percent reduction in the price of Russian gas on which Ukraine depends for much of its energy needs. AFP PHOTO / VIKTOR DRACHEV

Russian naval infantry soldiers (marines) stand behind the gates of their base as they guard the Orsk Russian landing ship anchored in the Ukraine's Black Sea port of Sevastopol on March 2, 2014, with a Russian naval flag painted on the gates. In 2010, after years of tortuous negotiations, Ukraine agreed to extend Moscow's lease on Sevastopol port until 2042 in exchange for a 30-percent reduction in the price of Russian gas on which Ukraine depends for much of its energy needs. AFP PHOTO / VIKTOR DRACHEV

Russian naval infantry soldiers (marines) stand guard the Orsk Russian landing ship anchored in the Ukraine's Black Sea port of Sevastopol on March 2, 2014, with a Russian naval flag painted on the gates. In 2010, after years of tortuous negotiations, Ukraine agreed to extend Moscow's lease on Sevastopol port until 2042 in exchange for a 30-percent reduction in the price of Russian gas on which Ukraine depends for much of its energy needs. AFP PHOTO / VIKTOR DRACHEV

Russian naval infantry soldiers (marines) walk as they guard the Orsk Russian landing ship anchored in the Ukraine's Black Sea port of Sevastopol on March 2, 2014, with a Russian naval flag painted on the gates. In 2010, after years of tortuous negotiations, Ukraine agreed to extend Moscow's lease on Sevastopol port until 2042 in exchange for a 30-percent reduction in the price of Russian gas on which Ukraine depends for much of its energy needs. AFP PHOTO / VIKTOR DRACHEV

An elderly man speaks with Russian naval infantry soldiers (marines) as they guard the Orsk Russian landing ship anchored in the Ukraine's Black Sea port of Sevastopol on March 2, 2014. In 2010, after years of tortuous negotiations, Ukraine agreed to extend Moscow's lease on Sevastopol port until 2042 in exchange for a 30-percent reduction in the price of Russian gas on which Ukraine depends for much of its energy needs. AFP PHOTO / VIKTOR DRACHEV