The Secretary-General of the United Nations has warned that the world is inching closer to a nuclear war and says humanity is playing with a “loaded gun.”

While speaking at a memorial site in Japan where the first nuclear bomb was dropped, Secretary-General Antonio Guterres said “Tens of thousands of people were killed in this city in the blink of an eye. Women, children, and men were incinerated in a hellish fire. We must ask: what have we learned from the mushroom cloud that swelled above this city? Crises with grave nuclear undertones are spreading fast. Humanity is playing with a loaded gun.”

The Secretary-General’s comments come as he continues pushing for nuclear non-proliferation measures globally.