French President Emmanuel Macron on Thursday defended his policy of keeping up a dialogue with Russia after its invasion of Ukraine, saying that Turkey should not be the only power talking to Moscow and preparations should already be made for a negotiated peace.

Macron has repeatedly spoken to Russian counterpart Vladimir Putin since Moscow launched its attack on Ukraine in February, with their latest conversation coming on August 19 following a lengthy pause.

Turkish President Recep Tayyip Erdogan, with whom Macron has had a fractious relationship, has meanwhile actively sought to play the role of mediator, meeting in person with both Putin and Ukrainian President Volodymyr Zelensky.

"Who wants Turkey to be the only world power which continues to talk to Russia?" the president told a meeting of French ambassadors at the Elysee Palace.

"We must not give in to any form of false morality which would leave us powerless," he added.

"The job of a diplomat is to talk to everyone, especially to people with whom we do not agree. And so we will continue to do so, in coordination with our allies."

Macron argued that world powers should already be preparing for a "negotiated peace" to end the conflict that has already lasted over half a year, while emphasising it was up to Kyiv to decide on the timing and the terms.

"We must prepare for a long war. We must avoid escalation and prepare the peace," he said.

"Preparing the peace means talking to all the parties including, as I did just a few days ago and will again, to Russia."

He said such a negotiated peace would not be on the terms "Ukraine would have been subjected to if we had abandoned it to its fate."

Macron argued that Western military assistance for Ukraine, including from France, had allowed the country to withstand the Russian invasion far more effectively than many experts and also Russia had predicted.

"We are not participating in the war, we do not want to," he said, repeating an argument Macron has used since the first days of the war.

"But we cannot let Russia win this war militarily by gaining territory and, at the same time, showing the defeat of the international order and our values on the basis of an aggression."

He also warned that Europe must keep up unity, noting that some countries were calling for a more bellicose stance or thinking of unilateral measures.

"We must not let Europe be divided by this war. European unity is key. The division of Europe was one of Russia's aim of the war," he said.