Japan urged to remember its atrocities in WWII, as Nagasaki marks 73rd anniversary of atomic bombing by US

Taue went on to say that the two atomic bombed cities of Hiroshima and Nagasaki have high hopes for "irreversible denuclearization."

The mayor urged the Japanese government to use the opportunity to create a nuclear-free zone in Northeast Asia.

Guterres, in his speech, meanwhile, called on all nations to commit to nuclear disarmament and urgently make "visible" progress.

"Disarmament processes have slowed and even come to a halt," Guterres said, intimating that the adoption last year of the Treaty on the Prohibition of Nuclear Weapons had shown the frustration that many countries had been feeling.

Prime Minister Shinzo Abe, for his part, said in his speech that "in recent years, differences in the approaches of various countries on nuclear disarmament have become evident."

He went on to say that Japan will serve as a bridge between nuclear powers and non-nuclear states, and that "an accurate understanding of the tragic realities of the atomic bombings and cooperation from both parties is essential."

While Japan this week inwardly looks at the tragedies it has experienced at the end of WWII, historians and political minds of the international community have encouraged Japan to come to see themselves not as merely victims of the atomic bombings but also as the perpetrators who led to these tragic incidents to happen in the first place.

Japan brutally occupied many parts of Asia before and during World War II, causing untold suffering and death to hundreds of thousands of innocent victims.

One fact, for example, that is finally garnering more and more attention around the world due to TV documentaries and scholars' research is the Japanese army's notorious Unit 731.

The unit was set up in the Pingfang district of Harbin, the largest city then in northeast China, in around 1936 and conducted vivisection experiments on live human beings to test germ-releasing bombs and chemical bombs among other criminal atrocities.