The southern Japanese city of Nagasaki on Tuesday remembered the victims of the atomic bombing of the city by the US 77 years ago.

The city's mayor, Tomihisa Taue, said current events showed that the only way to safeguard the future of humankind was to eliminate nuclear weapons.

What did Nagasaki's mayor say?

In his speech at the Nagasaki Peace Park, Taue said that while nuclear weapons existed, there was the possibility they would be used.

He pointed out that, in January, the five permanent members of the UN Security Council had pledged in a statement that nuclear war should never be fought.

However, one of the parties, Russia, invaded Ukraine only a month later. Russian President Vladimir Putin has warned that third party interference would result in "consequences you have never seen," a comment widely interpreted as a potential nuclear threat.

"Threats of using nuclear weapons have been made, sending shivers throughout the globe," Taue said. 

"The use of nuclear weapons is not a 'groundless fear,' but a 'tangible and present crisis,'" he added, saying that a nuclear cataclysm could arise through mistaken judgements, malfunctions or in terror attacks.

The mayor said that instead of starting wars, humanity needed to nurture "a culture of peace that spreads trust, respects others and seeks resolutions through dialogue."

Also speaking at the event was Japanese Prime Minister Fumio Kishida.

"Even though we face a severe security environment, we must pursue the history of non-nuclear use and make Nagasaki the last place of nuclear attack," Kishida said.

Japan has renounced the possession, production or hosting of nuclear weapons, although some lawmakers have proposed the possibility of sharing with the US in a deal that would be similar to the one in Germany.

Need to 'draw on lessons of Nagasaki'

Tuesday's ceremony saw survivors and foreign dignitaries, as well as members of the public, offering silent prayers at 11:02 a.m. (0202 GMT) — the exact moment the bomb was detonated over Nagasaki on August 9, 1945.

The port city was flattened in an explosion that killed up to 80,000 people — about half on the day of the attack and the rest in the months that followed as a result of burns, radiation sickness and injuries. This was compounded by the effects of disease and malnutrition.

The strike came just three days after the world's first nuclear bomb attack on the city of Hiroshima.

That bombing was even more deadly and claimed some 140,000 lives, including those who died in the aftermath.

The US had been trying out two different types of bomb: Little Boy, detonated over Hiroshima, was filled with uranium; Fat Man, detonated over Nagasaki, was filled with plutonium. The bomb dropped on Nagasaki was actually the more powerful of the two, but it did less damage because of Nagasaki's more uneven terrain.

Japan formally announced its surrender within a week of the attack on Nagasaki, on August 15, 1945. The deal was signed by September 2, ending World War II.

UN Secretary-General Antonio Guterres ​gave a speech at a commemoration in Hiroshima on Saturday​ in which he warned that humanity was playing "with a loaded gun" as the potential for nuclear disaster grows.

In a message read aloud in Japanese at Tuesday's ceremony, Guterres warned that "in these times of high tensions and low levels of trust, we should draw on the lessons of Nagasaki."

Nagasaki was bombed in place of the ancient city of Kyoto, which had been removed from the target list partly because the US Secretary of War, Henry Stimson, had honeymooned there decades earlier. He had said it was an important cultural center that "must not be bombed."

rc/msh (AFP, AP)