The International Campaign to Abolish Nuclear Weapons (ICAN) which brings together more than 450 organizations, was a driving force behind an international treaty on banning nuclear weapons that passed this year.
A survivor of the Hiroshima atomic bombing and the leader of the group that won this year's Nobel Peace Prize on Saturday urged the United States and North Korea to tone down their rhetoric and negotiate together to avoid a nuclear strike.
Tensions have risen markedly in recent months over North Korea's development, in defiance of repeated rounds of UN sanctions, of nuclear-tipped missiles capable of reaching the United States.
A missile test last week prompted a US warning that North Korea's leadership would be "utterly destroyed" if war were to break out. The Pentagon has mounted repeated shows of force after North Korean tests.
ICAN was awarded this year's Nobel Peace Prize by a Nobel committee that cited the spread of nuclear weapons by countries like North Korea and the growing risk of an atomic war.
Setsuko Thurlow, an 85-year-old survivor of the Hiroshima bombing on August 6, 1945, and Beatrice Fihn, ICAN's executive director, will receive the prize together on Sunday at Oslo City Hall in front of King Harald and Queen Sonja.
"No human being should suffer what we suffered," Thurlow, who was 13 at the time of the attack and is now an ICAN campaigner, told reporters on Saturday.
Haruka Nuga looks at the significance of the prize for nuclear bomb victims.