French President Francois Hollande will make an unscheduled stop in Moscow later on Saturday to discuss the Ukraine crisis with his Russian counterpart Vladimir Putin, his office said.

French President Francois Hollande will make an unscheduled stop in Moscow later on Saturday to discuss the Ukraine crisis with his Russian counterpart Vladimir Putin, his office said.

Hollande will stop in the Russian capital on his way back home from a visit to Kazakhstan, a day after vowing to work towards a "de-escalation" in the Ukraine crisis, it said in a statement.

He will likely meet Putin at an airport in Moscow, it added.

Warning that the eight-month Ukraine crisis posed "serious threats to the economy of the entire region", Hollande on Friday promised "to work together to find all the points that will allow... to initiate a de-escalation".

The European Union and the United States have imposed sanctions on Russia over the crisis.

Because of the tensions, France delayed delivery of two Mistral-class helicopter carriers that it was building for Russia in a 1.2 billion euro ($1.5 billion) contract.

Paris faces hefty fines if it breaches the contract with Russia, but risks the wrath of its allies around the world if it delivers the hot-button technology to Moscow with the Ukraine crisis still raging.