Russian President Vladimir Putin on Wednesday proposed an update to Russia's nuclear deterrence strategy amid its war in Ukraine.

"In the updated version of the document, aggression against Russia by any non-nuclear state but with the participation or support of a nuclear state is proposed to be considered as their joint attack on the Russian Federation," he said on Wednesday while meeting the country's most senior security committee on nuclear deterrence.

Russian officials have warned Western states of the possibility of nuclear war in the event of a direct confrontation.

Ukraine has been asking Western allies for permission to use long-range weapons to strike targets deep within Russian territory. Ukrainian forces have also held parts of Russia's Kursk border region since an incursion launched in August.

Also on Wednesday, Ukrainian President Volodymyr Zelenskyy alleged that Russia had planned potentially catastrophic attacks on Ukrainian nuclear power plants.

Moscow warns against attacking Belarus 

The Russian president also said Russia reserved "the right to use nuclear weapons" in response to an attack on Belarus.

Russia and Belarus have been integrated into a union state since a 1999 treaty. Belarus has served as a staging ground for Russia's invasion but has not itself sent troops to Ukraine.

"All these issues have been agreed with the Belarusian side, with the President of Belarus. Including if the enemy, using conventional weapons, creates a critical threat to our sovereignty,” Putin said-

 "We will consider such a possibility once we receive reliable information about a massive launch of air and space attack weapons and their crossing our state border," Putin said in his comments on Wednesday, adding that he was referring to "aeroplanes of strategic and tactical aviation, cruise missiles, drones, hypersonic and other aircraft."

What else did Putin say?

Russia's president said that the strategy entails "the basic principle of the use of nuclear weapons, namely, the use of nuclear forces is an extreme measure to protect the country's sovereignty."

"The conditions for Russia´s transition to the use of nuclear weapons are also clearly fixed," Putin said.

"We see the modern military and political situation is dynamically changing and we must take this into consideration," Putin said, citing "the emergence of new sources of military threats and risks for Russia and our allies."

He said that nuclear weapons are "the most important guarantee of security of our state and its citizens."

Putin said that Moscow had "always taken a highly responsible approach" to nuclear issues, saying that it aimed to strengthen "global stability" and "prevent the spread of nuclear weapons and their components."

sdi/dj (AFP, Reuters, AP)