PARIS (AFP) - France on Friday condemned plans by pro-Russian separatists in Ukraine to press on with "illegal" independence referendums this weekend and urged restraint.

French Foreign Minister Laurent Fabius said he had spoken to Ukrainian Prime Minister Arseniy Yatsenyuk ahead of Sunday's planned vote.

"France condemns the decision of the separatists in eastern Ukraine to hold these illegal referendums despite convergent calls to abstain," he said.

On Wednesday, Russian President Vladimir Putin stunned the world with a U-turn on Ukraine, calling on the pro-Russian separatists to delay the referendums, while welcoming a May 25 presidential election.

But the rebels holed up in more than a dozen towns and cities in eastern Ukraine have vowed to press ahead with votes in the Donetsk, Slavyansk and Lugansk regions.

"At this crucial moment all parties must show restraint," Fabius said, underscoring the need for dialogue.