Why are there still so many nuclear weapons?

The UN's International Day for the Total Elimination of Nuclear Weapons is 26 September.

There are far fewer nuclear weapons now than at the height of the Cold War and the major nuclear powers have all signed up to the principle of disarmament.

But there are fears of a renewed nuclear arms race between the US, Russia and China.

Reality Check's Jack Goodman takes a look at the facts and figures behind the world's nuclear arsenals.