Head of the Ukraine's National Security and Defence Council, Andriy Parubiy, speaks after a special council hearing in Kiev on March2, 2014. Ukraine said Sunday it would call up all military reservists after President Vladimir Putin's threat to invade Russia's neighbour drew a blunt response from US President Barack Obama. The stark escalation in what threatens to become the worst crisis in relations since the Cold War came as pro-Russian forces seized control of key government buildings and airports in the strategic Crimean peninsula. AFP PHOTO/ ANATOLIY STEPANOV

Head of the Ukraine's National Security and Defence Council, Andriy Parubiy, speaks after a special council hearing in Kiev on March2, 2014. Ukraine said Sunday it would call up all military reservists after President Vladimir Putin's threat to invade Russia's neighbour drew a blunt response from US President Barack Obama. The stark escalation in what threatens to become the worst crisis in relations since the Cold War came as pro-Russian forces seized control of key government buildings and airports in the strategic Crimean peninsula. AFP PHOTO/ ANATOLIY STEPANOV