"Our task is to hold our line, that is to say, help Ukraine as we are doing, to protect its territory and never to attack Russia," Macron told BFM television during his return from the UN General Assembly in New York on Wednesday.

"Russia is very clearly under pressure" but "I am not going to take part in any escalation" of the conflict, Macron added.

Putin has sparked alarm particularly in Europe with his threat of using "all the means at our disposal" to defend itself during its invasion of Ukraine, as he called up some 300,000 reservists for the fight.

Experts have warned about Putin's unpredictable responses to a recent counter-offensive by Ukraine that has seen it recover parts of territory seized by Russian troops since their invasion on February 24.

"Russia has decided to take a step toward escalation," Macron said, but "we must never get carried away."