Hiroshima, a Japanese city hit by a US atomic bomb at the end of World War II, marked the 74th anniversary of the bombing on Tuesday.

An annual memorial ceremony, held at the Peace Memorial Park near Ground Zero, was attended by about 50,000 audiences paying respect, including representatives from about 90 countries and regions.

Japanese Prime Minister Shinzo Abe delivered a speech during the ceremony, stressing the importance of continuing efforts to realize "a world free of nuclear weapons."

As the only country that has experienced atomic bombings in war, Japan's duty to eliminate nuclear weapons remains unchanged even in the Reiwa era, Abe said.

Japan is determination to serve tenaciously as a mediator between nuclear weapon states and non-nuclear weapon states and take the lead in making such efforts in the international community, he said.

Japan will also continue to promote policies considerate of "hibakusha," namely atomic bomb survivors in Japan, he added.

Kazumi Matsui, mayor of Hiroshima, delivered the Peace Declaration commemorating 74 years since the atomic bombing. He called on the central government to "accede" to the request from hibakusha that the UN Treaty on the Prohibition of Nuclear Weapons be "signed and ratified."

"I urge Japan's leaders to manifest the pacifism of the Japanese Constitution by displaying leadership in taking the next step toward a world free from nuclear weapons," Matsui said.

A uranium-core atomic bomb named "Little Boy," dropped onto Hiroshima in western Japan by a US bomber, exploded above the city at 8:15 a.m. local time on Aug. 6, 1945, killing an estimated 140,000 people by the end of the same year.

Nagasaki was also hit by an atomic bomb on Aug. 9, 1945, prompting Japan's surrender and the end of World War II.