India, June 18 -- Nine countries across the world either officially possess nuclear weapons or are widely believed to maintain them, with the United States, Russia, China, France, and the United Kingdom being the first to develop and declare such capability.

These five powers are recognised as nuclear-weapon states under the Nuclear Nonproliferation Treaty (NPT), which seeks to prevent the spread of nuclear arms while promoting disarmament.

India and Pakistan, neither of which has signed the Nuclear Nonproliferation Treaty (NPT), have gradually built up their nuclear arsenals.

India conducted its first nuclear test in 1974, followed by another in 1998. Within weeks, Pakistan carried out its own nuclear tests, marking its entry into the...