(Reuters) -Ukrainian President Volodymyr Zelenskiy said on Sunday that if Russia proceeded with referendums in occupied areas of his country on joining Russia, there could be no talks with Ukraine or its international allies. Russian forces and their separatist allies now hold large swathes of territory in eastern Ukraine’s Donbas region and in southern areas after launching what the Kremlin calls a “special military operation” into its neighbour’s territory. Officials in both areas have raised the possibility of holding referendums. In his nightly video address, Zelenskiy said Kyiv was holdin…