The agreement was signed on Wednesday in NY by more than 50 United Nations member states, but several nuclear powers, including the US, UK and France, boycotted the signing ceremony.
The Treaty will enter into force 90 days after it has been ratified by at least 50 countries.
The fact that it was approved by 122 countries and signed by almost 50 yesterday demonstrates "significant maturity on the part of most of the countries of the world, who will be the first victims of a nuclear holocaust", the president said.
There is nothing to prevent these countries from using nuclear weapons in future conflicts, and there is an excellent possibility that they will.
The United States, Britain, France and others, including Australia, boycotted the event at the annual United Nations gathering of world leaders on September 20.More news: Russian Helicopters Mistakenly Fire at Civilians During Exercise
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As the signature event began, UN Secretary-General Antonio Guterres noted that "we can not allow these doomsday weapons to endanger our world and our children's future".
"The so-called ban treaty is potentially an important milestone on a long-term path toward nuclear disarmament", he added.
Peter Maurer, the president of the International Committee of the Red Cross, also participated in the ceremony.
Moreover, several nuclear powers have effectively offset reductive progress by developing or deploying new nuclear weapon delivery systems, or announcing their intention to do so. The signing took place during the High Level Ceremony for the opening of the signing of the Treaty. Along with the Holy See, Thailand also ratified the treaty.
"If people believe that getting rid of nuclear weapons will lead to peace, a democratic government (sharing the belief) will be born, followed by the signing of the treaty", said Kunihiko Sakuma, 72, head of the hibakusha organization.
Nuclear weapons have defied attempts to contain their spread since the United States dropped two atomic bombs on Japan in 1945, ending World War II. More than 40 other countries signed it as well. Nuclear powers are also the only United Nations members with permanent Security Council veto power.