Russia on Sunday endorsed a crushing victory for Ukraine’s pro-Moscow separatists leadership at controversial polls that the EU slammed as a "new obstacle" for peace in the country’s strife-torn east.

Russia on Sunday endorsed a crushing victory for Ukraine's pro-Moscow separatists leadership at controversial polls that the EU slammed as a "new obstacle" for peace in the country's strife-torn east.

Despite warnings from Kiev and the West not to recognize the polls, Moscow moved quickly to throw its weight behind the disputed elections, deepening the international crisis over Ukraine.

"We respect the expression of the will of the residents of southeast (Ukraine)," the foreign ministry said in a statement, cited by Russian news agencies.

"Those elected have received a mandate to resolve the practical issues of re-establishing normal life in the region."

Just prior to Moscow's announcement, the European Union's top diplomat Federica Mogherini had already decried the separatist vote as a "new obstacle on the path to peace."

Ukrainian President Petro Poroshenko blasted the ballot as a "farce that is being conducted under the threat of tanks and guns" and the fear is they could now spell the end for a battered two-month ceasefire between government troops and armed separatists.

Fresh from claiming victory, top rebel Alexander Zakharchenko told journalists that "Ukraine does not want peace, as it claims. Obviously it is playing a double game."

Zakharchenko was on some 70 percent with some half of the votes counted, rebel electoral officials said.