Russia, which inherited the Soviet Union's nuclear weapons, has the world's biggest store of nuclear warheads.
Russian President Vladimir Putin controls around 5,977 warheads as of 2022, compared to 5,428 controlled by US President Joe Biden.
Around 1,500 of those warheads are retired (but probably still intact), 2,889 are in reserve and around 1,588 are deployed strategic warheads.
About 812 are deployed on land-based ballistic missiles, about 576 on submarine-launched ballistic missiles, and around 200 at heavy bomber bases.
US has around 1644 deployed strategic nuclear warheads. China has a total of 350 warheads, France 290 and the United Kingdom 225.
Such numbers mean that both Moscow and Washington could destroy the world many times over.
During the Cold War, the Soviet Union had a peak of around 40,000 nuclear warheads, while the US peak was around 30,000 warheads.
Russia appears to have about 400 nuclear-armed intercontinental ballistic missiles, which as per estimate can carry up to 1,185 warheads.
Russia operates 10 nuclear-armed nuclear submarines which could carry a maximum of 800 warheads. It has around 60 to 70 nuclear bombers.
The US, in its 2022 Nuclear Posture Review, said Russia and China were expanding and modernising their nuclear forces.
Putin had also information that the United States was developing new types of nuclear weapons. Russia has been modernising its nuclear weapons.
The United States last in 1992 China and France last in 1996 India and Pakistan in 1998 North Korea last in 2017 Soviet Union last tested in 1990
Since the Soviet Union collapsed in 1991, only a few countries have tested nuclear weapons: