Emmanuel Macron has urged Vladimir Putin to "come back to the table" and promised to deliver air defence systems to Ukraine, in the midst of a massive new Russian bombing campaign.
In a television interview, the French president criticised his Russian counterpart for having made the "choice" to involve Europe more in the war with the recent missile strikes and the general mobilisation order to reinforce the army.
"Today, first of all, Vladimir Putin must stop this war, respect the territorial integrity of Ukraine and come back to the discussion table," he told public television channel France 2 on Wednesday night.
This week's Russian missile bombardment targetting energy infrastructure and civilians was an attempt to break Ukrainian resistance, the president said, explaining his earlier comment that the escalation brought the war into a new phase.
Macron defended his refusal to break off dialogue with the Russian leader since the February invasion, despite criticism of his stance including from Ukrainians, saying he would continue to talk to Putin "whenever necessary".
He reiterated that it would ultimately be up to Ukraine to decide when the conditions for negotiation would be met and that the stated aim was clear: a return to the "1991 borders", before Russia's illegal annexation of Crimea in 2014, and of four Ukrainian regions at the end of September.
"The question is whether these war aims will only be achieved militarily," he said. "I believe that at some point it will be in the interest of Ukraine and Russia to come back to the table and negotiate."
"The stability of our continent is the concern of all of us... We will have roles to play as guarantors", he went on, accepting that no negotiations would take place "in the next few weeks" and that Europe had to prepare "to spend the winter in this context of war".
In the meantime, Macron said France would continue to provide military assistance to Ukraine by delivering "radars, systems and anti-aircraft missiles" to counter Russian bombing and drone attacks, as well as Caesar guns.
As NATO defence ministers met in Brussels, Paris said it would deliver its own anti-aircraft defence systems. France has also said it will reinforce its military presence on NATO's eastern flank in the coming weeks with additional troops, tanks and weapons.
The French president also had a warning for Alexander Lukashenko of Belarus, Moscow's main ally, saying he would be in "trouble" if he became more involved in the conflict. Earlier this week the country's authoritarian leader said he was ordering troops to deploy with Russian forces near its border with Ukraine, without giving any timings.
Macron said it was important to avoid an escalation with the conflict spreading to Ukraine's neighbours -- and to prevent Moscow from using chemical or nuclear weapons.
Addressing Putin's threats over the use of nuclear weapons, Macron reminded his audience that France also had a nuclear deterrent. "The less we talk about the threat the more credible we are," he said.
"Too many people are talking about it."
Following President Zelenskyy's call for more western equipment to provide an "aerial shield", Ukrainian Defence Minister Oleksiy Reznikov hailed "a new era of air defence" with the arrival of the IRIS-T system from Germany and the upcoming delivery of an American NASAMS air defence system.
The UK said on Thursday that it would provide Ukraine with additional air defence missiles, including munitions capable of shooting down cruise missiles.
Also on Thursday, 15 European countries announced that they would jointly procure air defence systems to protect the continent under a newly-created European Sky Shield Initiative, spearheaded by Germany.