“We cannot allow these doomsday weapons to endanger our world and our children’s future.”

Amid tensions over North Korea’s nuclear and missile tests, the 50 countries needed have signed the world’s first legally binding treaty banning nuclear weapons.

The treaty – adopted on 7 July by 122 UN member states during a United Nations conference in New York despite heavy US opposition – prohibits the development, testing, production, manufacture, acquisition, possession or stockpiling of nuclear weapons or other nuclear explosive devices, as well as their use or the threat to use them.