French Foreign Minister Laurent Fabius has confirmed the sale of two warships to Russia will go ahead, saying many jobs are at stake, BBC News reported.

"The contracts were agreed in 2011, they represent many jobs and they will be carried out," he said in a tweet.

U.S. President Barack Obama has said he is concerned about the sale, in light of the crisis in Ukraine. Both he and Russian President Vladimir Putin are due to attend D-Day events in France later on Friday, June 6.

French President Francois Hollande has come under sustained pressure from European allies over the Mistral-class helicopter carriers, which are set to be delivered to the Black Sea ports in Crimea, which joined Russia after a referendum in March.

The first carrier in the 1.2bn euro ($1.6bn) deal is due for delivery this year.

Obama said while he recognised it was a big deal and important for French jobs, "I think it would have been preferable to press the pause button".

Pro-Ukrainian bloggers reacted with anger to the tweet by Mr Fabius.

"Life/blood of non-compatriots are cheap," wrote one on Twitter, while another remarked "so French jobs more important than Ukrainian lives".