According to Stockholm International Peach Research Institute (SIPRI) , Russia and US together constitute around 93 percent of the world's nuclear weapons, And rest of the nukes are among the other 7 countries that are in the list.
Seeking to prevent the nuclear weapon ranks from expanding further,The United States and other like-minded states negotiated the Nuclear Nonproliferation Treaty (NPT) in 1968 .
Since the NPT entered into force , three states that were not parties to theTreaty have conducted nuclear tests, namely India, Pakistan, and North Korea. North Korea had been a party to the NPT but withdrew in 2003 .
It is said that countries like Russia and USA decreased the no. of nukes in the past couple of years but SIPRI points out that the rate of reduction has slowed down and spending on nuclear forces increased in recent years because of “ extensive and expensive modernisation programmes ”.
On the other hand North Korea is increasing it's nuclear power with quite a fast rate and the successful Hydrogen bomb test and other powerful nuclear tests are the recent evidences of that.
Source : https://www.sbs.com.au/news/which-nine-countries-have-nuclear-weapons
https://en.wikipedia.org/wiki/List_of_states_with_nuclear_weapons
