France on Tuesday pushed back "until further notice" the delivery of a controversial warship to Russia because of the Ukraine crisis, sparking a measured response from Moscow.

President Francois Hollande said in a statement that the "current situation in eastern Ukraine still does not allow for the delivery of the first" Mistral-class vessel France has built for Russia.

"He therefore decided to delay until further notice" the decision on whether to grant the export license needed to deliver the ship to Russia, the statement added.

Russia has reportedly warned Paris of "serious" consequences unless France delivers the first of two Mistral-class helicopter carriers on order by the end of November.

But Moscow's reaction was relatively calm after Hollande's announcement, with Deputy Defense Minister Yury Borisov saying Russia did not immediately intend to file a claim against France for breach of contract.

"We'll wait patiently . . .  So far we are not filing a claim anywhere," Borisov told RIA Novosti news agency.

The first of the two assault ships was supposed to be delivered earlier this month, according to the original deal signed in 2011.

But amid the Ukraine conflict and the rapid decline in the West's relations with Russia, France has come under intense pressure from its allies, particularly the United States, and in September postponed the delivery.

Paris faces a serious dilemma over the Mistrals.

It could be liable for hefty fines if it breaches the 1.2-billion-euro ($1.5-billion) contract.

But it also risks the wrath of its allies around the world if it were to deliver the hot-button technology to Russia at a time when Moscow is in the diplomatic deep-freeze over the Ukraine unrest.

"Whatever our future decision, half of the world will have it in for us," a top-level French official who declined to be named said earlier this month.

However, Borisov told the ITAR-TASS news agency that if France ultimately refused to hand over the ship, Russia would "go to court and impose fines."

"Everything is written in the contract. We will act according to the wording of the contract, like all civilized people," Borisov said.

Foreign Minister Laurent Fabius said earlier Tuesday that the "conditions for delivery are not met, for reasons that are obvious today."

"On the Russian side, there is an unacceptable direct or indirect presence on the side of the separatists but on the Ukrainian side there are unacceptable declarations as well," said the minister, referring to Kiev's recently stated wish to join NATO.