Former Russian President Vladimir Putin's aide Vladislav Surkov has said Ukraine "may be regained only by force." Read alsoPurported phone call between Medvedchuk, Surkov leaked (Transcript)Surkov added the Russian Federation allegedly "wins the international situation." Earlier, Ukrainian media published what they claimed was a leaked recording of a conversation that took place in 2014 between Vladimir Putin's ally in Ukraine, MP Viktor Medvedchuk and Surkov, where they discussed power supplies to occupied Crimea and prisoner exchange in Donbas.