The conflict in Ukraine has triggered the worst crisis in Russia's relations with the West since the 1962 Cuban Missile Crisis and President Vladimir Putin has previously warned of the dangers of a direct confrontation between NATO and Russia.

French President Emmanuel Macron opened the door on Monday to European nations sending troops to Ukraine, although he cautioned that there was no consensus at this stage.

"The very fact of discussing the possibility of sending certain contingents to Ukraine from NATO countries is a very important new element," Kremlin spokesman Dmitry Peskov told reporters when asked about Macron's remarks.

Asked by reporters about the risks if NATO members sent their troops to fight in Ukraine, Peskov said: "In that case, we would need to talk not about the probability, but about the inevitability (of a direct conflict)."

Peskov said that the West should ask themselves if such a scenario was in the interests of their countries and their peoples.