Representatives of 71 countries attended the ceremony, including US Ambassador to Japan William Hagerty and Prime Minister Shinzo Abe. At the ringing of a bell, participants observed a minute’s silence at 11h02, the exact time the bomb was dropped on Nagasaki.
Emperor Akihito joined a silent prayer from Tokyo with his wife Michiko as they monitored the ceremony on TV, marking the last Nagasaki commemoration before his planned abdication next April.
The annual memorial ceremony was also attended by about 5,200 people including Nagasaki atomic bomb survivors and bereaved families of victims.
Nagasaki Mayor Tomihisa Taue, in his peace declaration, also urged the Japanese government to support an international nuclear ban treaty adopted last year.
"I hereby ask that the Government of Japan, the only country to have suffered from the wartime use of nuclear weapons, support the Treaty on the Prohibition of Nuclear Weapons and fulfill its moral obligation to lead the world towards denuclearization," Taue said.
Nagasaki was the second city to be targeted in 1945, only three days after Hiroshima. The atomic bombings took place late in the World War II and heralded the start of the nuclear age.
UN Secretary General Guterres was visiting Japan to attend the event.
He was the first UN leader to attend the Nagasaki ceremony, while his predecessor Ban Ki-moon attended the memorial service in Hiroshima in 2010.
The August 6th, 1945, the bombing of Hiroshima killed 140,000 people, and the bombing on Nagasaki three days later killed another 70,000, promoting Japan’s surrender in the World War II./.