Survivors of the atomic bombings of Hiroshima and Nagasaki have welcomed the awarding of the 2017 Nobel Peace Prize to an international group campaigning to eliminate nuclear weapons, but voiced frustration that Japan has still not joined an international treaty banning them.

"The young people's activities have been recognized," Toshiyuki Mimaki, 75, of the Hiroshima Prefectural Confederation of A-Bomb Sufferers Organizations, told fellow member Seiko Ikeda, 85, after the two watched the Nobel broadcast side by side in Hiroshima on Friday.

The award to the International Campaign to Abolish Nuclear Weapons (ICAN), follows the adoption in July of the Treaty on the Prohibition of Nuclear Weapons. ICAN had worked with hibakusha in its campaign for the treaty.