TANZANIA, TANZANIA -- The 193 members of the United Nations reached agreement on a declaration to commemorate this year's 75th anniversary of the world organization, recalling the UN's successes and failure and vowing to build a post-pandemic world that is more equal, works together, and protects the planet.

General Assembly President Tijjani Muhammad-Bande announced the agreement Tuesday in a letter to UN members. He said the declaration will be adopted by world leaders at the official anniversary commemoration on Sept. 21, which will be virtual because of the COVID-19 pandemic.

Born out of the horrors of the Second World War with a mission to save succeeding generations from the scourge of war, the United Nations is praised in the declaration as the only global organization that "gives hope to so many people for a better world and can deliver the future we want." It also says no other world body has the legitimacy or the power to convene leaders and people from all walks of life, and the impact of the United Nations.

"The urgency for all countries to come together, to fulfil the promise of the nations united, has rarely been greater," the declaration says.

Touting the UN's accomplishments, its member nations said "even in times of great global challenges and tension, our organization has catalyzed decolonization, promoted freedom, shaped norms for international development, and worked to eradicate disease."

"The United Nations has helped mitigate dozens of conflicts, saved hundreds of thousands of lives through humanitarian action and provided millions of children with the education that every child deserves," they said. "It has worked to promote and protect all human rights and fundamental freedoms for all, including the equal rights of women and men."

Over the decades, the nations said more than 1 million men and women have served in over 70 UN peacekeeping operations around the world.

As for disappointments, UN member nations said, the world "is plagued by growing inequality, poverty, hunger, armed conflicts, terrorism, insecurity, climate change, and pandemics." The poorest and least developed countries are falling behind, decolonization is not complete, and people "are forced to make dangerous journeys in search of refuge and safety," they added.

"All this calls for greater action, not less," the declaration stresses.

The UN members said the COVID-19 pandemic has become "the largest global challenge in the history of the United Nations" in a matter of weeks.

"Multilateralism is not an option but a necessity as we build back better for a more equal, more resilient, and more sustainable world," the declaration says. "The United Nations must be at the centre of our efforts."

The declaration was supposed to be approved by June 30, but diplomats said it was delayed because the United States demanded a change to the reference to the landmark 2015 Paris climate agreement to tackle global warming. They spoke on condition of anonymity because discussions were private.

U.S. President Donald Trump has started the process of pulling the U.S. out of the Paris accord. The revised language makes clear that the reference in the declaration doesn't refer to all countries but to commitments made by countries supporting the Paris agreement.