Ukrainian parliament speaker Oleksandr Turchynov answers media questions after an urgent parliament session in Kiev, Ukraine, Sunday, March 2, 2014. Ukraine's new prime minister urged Russian President Vladimir Putin to pull back his military Sunday in the conflict between the two countries, warning that "we are on the brink of disaster." The comments from Arseniy Yatsenyuk came as a convoy of Russian troops rolled toward Simferopol, the capital of Ukraine's Crimea region, a day after Russian forces took over the strategic Black Sea peninsula without firing a shot. (AP Photo/Andrew Kravchenko, Pool)

Ukrainian Prime Minister Arseniy Yatsenyuk answers media questions after an urgent parliament session in Kiev, Ukraine, Sunday, March 2, 2014. Ukraine's new prime minister urged Russian President Vladimir Putin to pull back his military Sunday in the conflict between the two countries, warning that "we are on the brink of disaster." The comments from Arseniy Yatsenyuk came as a convoy of Russian troops rolled toward Simferopol, the capital of Ukraine's Crimea region, a day after Russian forces took over the strategic Black Sea peninsula without firing a shot. (AP Photo/Andrew Kravchenko, Pool), APTOPIX

Ukrainian Prime Minister Arseniy Yatsenyuk (R) looks on as Olexander Turchynov, speaker of the parliament and interim Ukrainian president, speaks to the media after closing a session of parliament in Kiev on March 2, 2014. Ukraine said on March 2 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/ ANATOLII STEPANOV

Ukrainian Prime Minister Arseniy Yatsenyuk (R) speaks to the media, flanked by Olexander Turchynov, speaker of the parliament and interim Ukrainian president, after closing a session of parliament in Kiev on March 2, 2014. Ukraine said on March 2 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/ ANATOLII STEPANOV

Olexander Turchynov, speaker of the parliament and interim Ukrainian president, speaks to the media, flanked by Ukrainian Prime Minister Arseniy Yatsenyuk, after closing a session of parliament in Kiev on March 2, 2014. Ukraine said on March 2 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/ ANATOLII STEPANOV

Ukrainian Prime Minister Arseniy Yatsenyuk (R) speaks to the media, flanked by Olexander Turchynov, speaker of the parliament and interim Ukrainian president, after closing a session of parliament in Kiev on March 2, 2014. Ukraine said on March 2 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/ ANATOLII STEPANOV