A dockyard worker watches as barley grain is mechanically poured into a 40,000 ton ship at Ukrainian agricultural exporter's shipment terminal in the Black Sea port of Nikolayev, now known as Mykolaiv, Ukraine, in this July 9, 2013 file photo. REUTERS/Vincent Mundy/Files

Ukrainian Prime Minister Arseny Yatseniuk looks out from an armored ambulance at an armoured repair plant in the city of Mykolaiv, also known as Nikolayev, in southern Ukraine, October 11, 2014. REUTERS/Andrew Kravchenko/Pool (UKRAINE - Tags: MILITARY POLITICS CIVIL UNREST CONFLICT)

Ukrainian businessman, politician and presidential candidate Petro Poroshenko (C) meets with members of the National Guard of Ukraine in Mykolaiv in southern Ukraine, May 12, 2014. REUTERS/Mykola Lazarenko/Pool (UKRAINE - Tags: POLITICS MILITARY ELECTIONS BUSINESS)

Ukrainian businessman, politician and presidential candidate Petro Poroshenko (R) meets with members of the National Guard of Ukraine in Mykolaiv in southern Ukraine, May 12, 2014. REUTERS/Mykola Lazarenko/Pool (UKRAINE - Tags: POLITICS MILITARY ELECTIONS BUSINESS)

Ukrainian businessman, politician and presidential candidate Petro Poroshenko (C) visits a pro-Ukrainian checkpoint on the outskirts of Mykolaiv in southern Ukraine, May 12, 2014. REUTERS/Mykola Lazarenko/Pool (UKRAINE - Tags: POLITICS MILITARY ELECTIONS BUSINESS)

Ukrainian businessman, politician and presidential candidate Petro Poroshenko (R) visits a pro-Ukrainian checkpoint on the outskirts of Mykolaiv in southern Ukraine, May 12, 2014. REUTERS/Mykola Lazarenko/Pool (UKRAINE - Tags: POLITICS MILITARY ELECTIONS BUSINESS)

Firefighters work outside a multi-story apartment block, which was destroyed by an explosion, in Mykolaiv in southern Ukraine, May 12, 2014. At least three people were killed by the explosion, according to local media. The cause of the blast is currently unknown. REUTERS/Mykola Lazarenko/Pool (UKRAINE - Tags: DISASTER)

A view shows a multi-story apartment block, which was destroyed by an explosion, in Mykolaiv in southern Ukraine, May 12, 2014. At least three people were killed by the explosion, according to local media. The cause of the blast was currently unknown. REUTERS/Mykola Lazarenko/Pool (UKRAINE - Tags: DISASTER)

People gather near a multi-story apartment block, which was destroyed by an explosion, in Mykolaiv in southern Ukraine, May 12, 2014. At least three people were killed by the explosion, according to local media. The cause of the blast is currently unknown. REUTERS/Mykola Lazarenko/Pool (UKRAINE - Tags: DISASTER)

Firefighters stand near a multi-story apartment block, which was destroyed by an explosion, in Mykolaiv in southern Ukraine, May 12, 2014. At least three people were killed by the explosion, according to local media. The cause of the blast is currently unknown. REUTERS/Mykola Lazarenko/Pool (UKRAINE - Tags: DISASTER)

A firefighter (R) works near a multi-story apartment block, which was destroyed by an explosion, in Mykolaiv in southern Ukraine, May 12, 2014. At least three people were killed by the explosion, according to local media. The cause of the blast is currently unknown. REUTERS/Mykola Lazarenko/Pool (UKRAINE - Tags: DISASTER)

A helicopter, bearing a United Nations sign, is seen during a military drill conducted by Ukrainian servicemen near the city of Mykolaiv, also known as Nikolayev, in southern Ukraine, northwest of the Crimean peninsula March 14, 2014. REUTERS/Valentyn Ogirenko (UKRAINE - Tags: MILITARY POLITICS)

A Ukrainian serviceman takes part in a military drill near the city of Mykolaiv, also known as Nikolayev, in southern Ukraine, northwest of the Crimean peninsula March 14, 2014. REUTERS/Valentyn Ogirenko (UKRAINE - Tags: MILITARY POLITICS)

Ukrainian servicemen take part in a military drill near the city of Mykolaiv, also known as Nikolayev, in southern Ukraine, northwest of the Crimean peninsula March 14, 2014. REUTERS/Valentyn Ogirenko (UKRAINE - Tags: MILITARY POLITICS)

Tanks drive during a military drill conducted by Ukrainian servicemen near the city of Mykolaiv, also known as Nikolayev, in southern Ukraine, northwest of the Crimean peninsula March 14, 2014. REUTERS/Valentyn Ogirenko (UKRAINE - Tags: MILITARY POLITICS)

Tanks drive during a military drill conducted by Ukrainian servicemen near the city of Mykolaiv, also known as Nikolayev, in southern Ukraine, northwest of the Crimean peninsula March 14, 2014. REUTERS/Valentyn Ogirenko (UKRAINE - Tags: MILITARY POLITICS)

Ukrainian servicemen take part in a military drill near the city of Mykolaiv, also known as Nikolayev, in southern Ukraine, northwest of the Crimean peninsula March 14, 2014. REUTERS/Valentyn Ogirenko (UKRAINE - Tags: MILITARY POLITICS)

A Ukrainian serviceman takes part in a military drill near the city of Mykolaiv, also known as Nikolayev, in southern Ukraine, northwest of the Crimean peninsula March 14, 2014. REUTERS/Valentyn Ogirenko (UKRAINE - Tags: MILITARY POLITICS)

Ukrainian servicemen take part in a military drill near the city of Mykolaiv, also known as Nikolayev, in southern Ukraine, northwest of the Crimean peninsula March 14, 2014. REUTERS/Valentyn Ogirenko (UKRAINE - Tags: MILITARY POLITICS)

A Ukrainian serviceman stands guard during a military drill near the city of Mykolaiv, also known as Nikolayev, in southern Ukraine, northwest of the Crimean peninsula March 14, 2014. REUTERS/Valentyn Ogirenko (UKRAINE - Tags: MILITARY POLITICS)

Helicopters are seen during a military drill conducted by Ukrainian servicemen near the city of Mykolaiv, also known as Nikolayev, in southern Ukraine, northwest of the Crimean peninsula March 14, 2014. REUTERS/Valentyn Ogirenko (UKRAINE - Tags: MILITARY POLITICS)

Ukrainian servicemen take part in a military drill near the city of Mykolaiv, also known as Nikolayev, in southern Ukraine northwest of the Crimean peninsula March 14, 2014. REUTERS/Valentyn Ogirenko (UKRAINE - Tags: MILITARY POLITICS TPX IMAGES OF THE DAY)

Ukrainian servicemen take part in a military drill near the city of Mykolaiv, also known as Nikolayev, in southern Ukraine, northwest of the Crimean peninsula March 14, 2014. REUTERS/Valentyn Ogirenko (UKRAINE - Tags: MILITARY POLITICS)

Ukrainian servicemen take part in a military drill near the city of Mykolaiv, also known as Nikolayev, in southern Ukraine, northwest of the Crimean peninsula March 14, 2014. REUTERS/Valentyn Ogirenko (UKRAINE - Tags: MILITARY POLITICS)

Ukrainian servicemen take part in a military drill near the city of Mykolaiv, also known as Nikolayev, in southern Ukraine, northwest of the Crimean peninsula March 14, 2014. REUTERS/Valentyn Ogirenko (UKRAINE - Tags: MILITARY POLITICS)

Ukrainian servicemen take part in a military drill near the city of Mykolaiv, also known as Nikolayev, in southern Ukraine, northwest of the Crimean peninsula March 14, 2014. REUTERS/Valentyn Ogirenko (UKRAINE - Tags: MILITARY POLITICS)

Ukrainian serviceman receives welcoming bread and salt from girl in a national costume at air base near Mykolaiv. A Ukrainian serviceman receives the welcoming bread and salt from a girl dressed in national costume during a ceremony at an air base near Mykolaiv, about 500 km south of the capital Kiev, March 15, 2005. The first group of 137 Ukrainian troops returned home as Ukraine started the gradual withdrawal of its international peacekeeping contingent from Iraq, Interfax news agency reported. REUTERS/Gleb Garanich

Ukrainian servicemen listen to the national anthem after their arrival from Iraq, at an air base near Mykolaiv, about 500 km south of the capital Kiev, March 15, 2005. The first group of 137 Ukrainian troops returned home as Ukraine started the gradual withdrawal of its international peacekeeping contingent from Iraq, Interfax news agency reported. REUTERS/Gleb Garanich YYK/AS/WS

Ukrainian servicemen observe moment of silence at air base near Mykolaiv to commemorate their colleagues who died during the war in Iraq. Ukrainian servicemen observe a moment of silence to remember their colleagues who died during the war in Iraq, after landing at an air base near Mykolaiv, about 500 km south of the capital Kiev, March 15, 2005. The first group of 137 Ukrainian troops returned home as Ukraine started the gradual withdrawal of its international peacekeeping contingent from Iraq, Interfax news agency reported. REUTERS/Gleb Garanich

Ukrainian servicemen march past a brass band upon their arrival from Iraq, at an air base near Mykolaiv, about 500 km south of the capital Kiev, March 15, 2005. The first group of 137 Ukrainian troops returned home as Ukraine started the gradual withdrawal of its international peacekeeping contingent from Iraq. The pull-out is likely to be completed by the end of this year, Interfax news agency reported. REUTERS/Gleb Garanich YYK/AS/WS

Ukrainian servicemen march past an aircraft after their arrival from Iraq, at an air base near Mykolaiv, about 500 km south of the capital Kiev, March 15, 2005. The first group of 137 Ukrainian troops returned home as Ukraine started the gradual withdrawal of its international peacekeeping contingent from Iraq. The pull-out is likely to be completed by the end of this year, Interfax news agency reported. REUTERS/Gleb Garanich YYK/AS/WS

Musicians of a military brass orchestra march along lined-up APCs after a farewell ceremony to Ukraine's Fourth military engineering battalion in Ukraine's southern town of Mykolaiv, December 11, 2000. The 500 men-strong battalion will be relocated to Sierra-Leone by the end of December to serve as a part of United Nations's peacekeeping forces.

YK/CVI

Soldiers of Ukraine's Fourth military engineering battalion line up for a farewell ceremony next to their lorries in Ukraine's southern town of Mykolaiv, December 11, 2000. The 500 men-strong battalion will be relocated to Sierra Leone by the end of December to serve as a part of the United Nations's peacekeeping forces.

YK/CVI

Musicians of a military brass band are reflected in a puddle as they perform during a farewell ceremony for Ukraine's Fourth military engineering battalion in Ukraine's southern town of Mykolaiv, December 11, 2000. The 500 men-strong battalion will be relocated to Sierra Leone by the end of December to serve as a part of United Nations's peacekeeping forces.

YK/CVI

An Orthodox priest sprays holy water on soldiers of Ukraine's Fourth military engineering battalion during farewell ceremony in Ukraine's southern town of Mykolaiv December 11, 2000. The 500 men-strong battalion will be relocated to Sierra Leone by the end of December to serve as a part of the United Nations's peacekeeping forces.

YK/CVI

A navy officer lifts up the Ukrainian flag aboard the 'Ukraine', a battle cruiser in Ukrainian Black Sea port of Mykolaiv, June 17. The 'Ukraine' which is the Ukraine navy's largest vessel, raised its flags for the first time on Thursday.

YK/CVI/WS

Ukrainian President Leonid Kuchma (R) greets a sailor aboard the 'Ukraine', a battle cruiser in the Ukrainian Black Sea port of Mykolaiv, June 17. The Ukraine, which is the Ukraine navy's largest vessel, raised its flags for the first time on Thursday. The building of the battle ship began in 1984, under the former Soviet Union.

YK/CVI/WS