Russian President Vladimir Putin warned Saturday that Moscow would consider any country imposing a no-fly zone over Ukraine to have entered into the conflict, while he also equated global sanctions with a declaration of war.
Ukrainian leader Volodymyr Zelensky has pleaded with the West to support a no-fly zone as his besieged country continues to resist Moscow's invasion, now in its second week.
Putin, who has dubbed his incursion a "special military operation" to defend separatist regions and previously argued that Ukrainian statehood is a fiction, also threatened his ex-Soviet neighbour's continued existence should its leaders "do what they are doing".
While Kyiv's allies have levelled sweeping sanctions to try to deter the Russian assault, they have so far ruled out a no-fly zone, fearing it could escalate into a wider war with the world's most nuclear-armed state.
Putin warned that a no-fly zone would have "colossal and catastrophic consequences not only for Europe but also the whole world".
"Any movement in this direction will be considered by us as participation in an armed conflict by that country," the Russian leader said during a meeting with employees of national airline Aeroflot.
He also suggested Kyiv's actions could cause Ukraine to lose its sovereignty.
"The current (Ukrainian) authorities must understand that if they continue to do what they are doing, they are putting in question the future of Ukrainian statehood," he said at the weekend gathering. "And if this happens, they will be fully responsible."
With the economic and humanitarian toll of the war spiralling, civilians have fled both Ukraine and Russia, where a clampdown is under way.
But Putin dismissed rumours that the Kremlin was planning to declare martial law in Russia.
"Martial law should only be introduced in cases where there is external aggression ... we are not experiencing that at the moment and I hope we won't," he said.
