Russian President Vladimir Putin has approved lowering the threshold for the country's use of nuclear weapons. His move follows recent media reports that US president Joe Biden's administration has given Ukraine permission to use long-range missiles to strike inside Russia.

Putin signed a decree on Tuesday ratifying the country's revised nuclear doctrine that stipulates the conditions for using nuclear arms.

The new doctrine implies that Moscow will view an attack from a non-nuclear state, carried out with participation and support of a nuclear state, as their joint attack.

The document also indicates that Russia could consider a nuclear strike if it obtains credible information about a massive launch of drones, cruise missiles and other weapons crossing the border into Russia.

Russia's presidential office spokesperson Dmitry Peskov said nuclear deterrence is aimed at ensuring a potential adversary understands that retaliation is inevitable in the event of an aggression against Russia and its allies.