The agreement by the signatories to the Nuclear Nonproliferation Treaty was reached after all-night deliberations and intense pressure on Iraq and the United States to settle a dispute over Baghdad's nuclear compliance.
The agreement says the five nuclear powers will make an "unequivocal" commitment to eventually eliminate their weapons.
The five-year conference to review the global treaty aimed at controlling and ultimately eliminating nuclear weapons required a consensusand the U.S.-Iraq dispute threatened to sabotage approval of a final document.
But many delegates were determined not to leave empty-handed and pressured Washington and Baghdad to compromise.
Mexico's disarmament ambassador in Geneva, Antonio de Icaza, speaking on behalf of a coalition of non-nuclear states that played a key role in negotiating the new agenda, urged the two countries "to go that extra mile."
Signaling the importance Washington placed on the issue of Iraq's compliance with nuclear agreements, U.S. Assistant Secretary of State Robert Einhorn, who is in charge of nonproliferation, flew to New York to take part in the final talks.
Hours after his arrival, Canadian Ambassador Chris Westdal, who had worked through the night, announced an agreement to applauding delegates, saying "the last piece in our puzzle is complete."
Delegates to the conference said the new nuclear agenda was important because it represented the first time in 15 years that the 187 nuclear and non-nuclear states were able to reach a consensus.
Secretary-General Kofi Annan said it "marks a significant step forward in humanity's pursuit of a more peaceful world a world free of nuclear dangers, a world with strengthened global norms for nuclear nonproliferation and disarmament."
By EDITH M. LEDERER