Japan will not join the first meeting of parties to a U.N. treaty banning nuclear weapons to be held in Vienna next week, Prime Minister Fumio Kishida said Wednesday, despite high expectations for its attendance as the only nation that has suffered atomic bombings.

Japan, which has not signed the Treaty on the Prohibition of Nuclear Weapons, did not complete the procedures for taking part in the three-day meeting, including as an observer, by the Tuesday deadline.

Survivors of the U.S. atomic bombings of Hiroshima and Nagasaki in August 1945, as well as member nations of the U.N. treaty, had hoped that the Japanese government would participate in the gathering that kicks off next Tuesday.