NATO chief Jens Stoltenberg warned Russia on Friday against recognizing elections staged by separatists in eastern Ukraine, saying Moscow continues to destabilize the country instead of backing peace efforts.

NATO chief Jens Stoltenberg warned Russia on Friday against recognizing elections staged by separatists in eastern Ukraine, saying Moscow continues to destabilize the country instead of backing peace efforts.

"Statements by Russian officials that Russia would recognize these so-called 'elections' show that Russia continues its efforts to destabilize Ukraine,"  Stoltenberg said in a statement.

"NATO allies, as part of the broad international community, have made clear they will not recognize so-called separatist elections."

Stoltenberg, the former Norwegian prime minister who took the helm at NATO this month, said Sunday's vote in Ukraine's Donetsk and Luhansk regions also undermined efforts to find a peaceful solution to a conflict which has cost more than 3,700 lives since fighting broke out in April.

The separatist polls "run directly counter" to the Minsk peace accords signed last month by Kiev with the separatists, he said.

"I call on Russia to respect its Minsk commitments, which could help pave the way for a peaceful solution."

The statement came after Putin, Ukrainian President Petro Poroshenko, French President Francois Hollande and German Chancellor Angela Merkel had a four-way telephone conversation.

The Kremlin said the four leaders agreed that the ceasefire deal should be observed while Moscow called for "dialogue" between Kiev and the separatists.