Norwegian Nobel Committee chair Jorgen Frydnes delivered a speech at Sophia University in Tokyo on Sunday, highlighting the need to listen to the voices of hibakusha, who survived the 1945 atomic bombings of Hiroshima and Nagasaki.

Hibakusha are "not only victims of war" but also "witnesses and teachers," Frydnes, 40, said during the Nobel Peace Prize Conference, hosted by the Norwegian Nobel Institute, which serves as the secretariat of the committee.

"You (hibakusha) have turned ashes into testimony and testimony into global awareness. Over time, an international norm took shape ... that stigmatizes the use of nuclear weapons as morally unacceptable. That norm is often referred to as the nuclear taboo," the committee chair noted.