SLOVYANSK, UKRAINE - APRIL 24: Vyachislav Ponomaryov, the self-appointed pro-Russian separatist mayor of the city of Slovyansk, holds his daily news conference on April 24, 2014 in Slovyansk, Ukraine. Pro-Russian activists have been occupying government buildings and demanding greater autonomy in many Eastern Ukrainian cities in recent weeks, prompting the government in Kiev to threaten military action to retake control of the cities. (Photo by Brendan Hoffman/Getty Images)