Russian President Vladimir Putin says that a nuclear power supporting another country’s attack on Russia will be considered a participant in aggression.

Speaking during Wednesday’s meeting of Russia’s Security Council, which considers changes in Russia’s nuclear doctrine, Mr Putin announced that a revised version of the document says that an attack against Russia by a non-nuclear power with support of a nuclear power will be seen as their “joint attack on the Russian Federation”.

Mr Putin did not specify whether Russia could respond to such an attack with nuclear weapons.

The change in the doctrine follows Mr Putin’s warning to the US and other Nato allies that allowing Ukraine to use Western-supplied long-range weapons for strikes on Russia would mean that Russia and Nato are at war.

Since Mr Putin sent troops into Ukraine in 2022, he and other Kremlin voices have frequently threatened the West with Russia’s nuclear arsenal to discourage it from ramping up support for Kyiv.

The current doctrine says Moscow could use its nuclear arsenal “in response to the use of nuclear and other types of weapons of mass destruction against it and/or its allies, as well as in the event of aggression against the Russian Federation with the use of conventional weapons when the very existence of the state is in jeopardy”.

The revised version of the document spells out conditions of nuclear weapons use in greater detail, noting they could be used in case of a massive air attack involving aircraft, cruise missiles or drones, he said.