The UN chief has called for the abolition of nuclear weapons on his first visit to the Japanese city of Nagasaki.
Secretary-General Ban Ki-moon said in a speech Thursday that nations must work together to ensure a world free from atomic bombs.
It was the UN chief's first visit to Nagasaki, the second Japanese city devastated by a US atomic bomb on August 9, 1945.
About 74,000 people were killed in Nagasaki.
Nagasaki was flattened just three days after an American B-29 bombed Hiroshima on August 6, 1945.
An estimated 140,000 people were killed instantly or died within a few months in Hiroshima.