Hiroshima marked the 74th anniversary of the atomic bombing of the city with its mayor renewing calls for eliminating such weapons and demanding Japan's government do more.

Mayor Kazumi Matsui raised concerns in his peace address Tuesday about the rise of self-centred politics in the world and urged leaders to steadily work toward achieving a world without atomic weapons.

"Around the world today, we see self-centred nationalism in ascendance, tensions heightened by international exclusivity and rivalry, with nuclear disarmament at a standstill," Matsui said in his peace declaration.

He urged the younger generations never to dismiss the atomic bombings and the Second World War as mere events of history, but think of them as their own, while calling on the world leaders to come visit Japan's two nuclear-bombed cities to learn what happened.

Matsui also demanded Japan's government represent the wills of atomic bombing survivors and sign a United Nations nuclear weapons ban treaty.

The U.S. attack on Hiroshima on Aug. 6, 1945 killed 140,000 people. The bomb dropped three days later on Nagasaki killed another 70,000 before Japan's surrender ended the Second World War.

The Atomic Bomb Dome was the only structure left standing in the area when the atomic bomb exploded on Aug. 6, 1945. (Kyodo News/The Associated Press)

Japan, which hosts 50,000 American troops and is protected by the U.S. nuclear umbrella, has not signed the Treaty on the Prohibition of Nuclear Weapons, an inaction atomic bombing survivors and pacifist groups protest as insincere.

Prime Minister Shinzo Abe acknowledged widening differences between nuclear and non-nuclear states.

"Japan is committed to serve as a bridge between nuclear and non-nuclear states and lead the international effort, while patiently trying to convince them to co-operate and have a dialogue," Abe said in his address at the Hiroshima anniversary ceremony. He vowed to maintain Japan's pacifist and nuclear nuclear-free principles, but did not promise signing the treaty.

Survivors, their relatives and other participants marked the 8:15 a.m. blast with a minute of silence.

The ceremony came hours after North Korea launched projectiles into the sea. Its recent weapons tests follow a stalemate in negotiations over its nuclear weapons.