VATICAN CITY (CNS) -- Kicking off a global meeting of leaders, Pope Francis told former U.S. President Bill Clinton and the global community to take action to ensure peace for future generations and stop climate change "before it's too late."

Opening the 2023 Clinton Global Initiative meeting of leaders in New York City Sept. 18, Clinton asked the pope, connected by video call, what ordinary people can do to address society's towering problems.

"We are in need of a great and shared assumption of responsibility," the pope said, adding that "no challenge is too great if we each meet it with personal conversion and the personal contribution that each of us can make to solve it from an awareness of what makes us part of one destiny."

"Difficulties can bring out the best or the worst in us," he said. "Therein lies our challenge: fighting selfishness, narcissism, division, with generosity and humility."

Started in 2005, the Clinton Global Initiative aims to bring leaders to create and implement solutions to the world's most pressing challenges. Participants for 2023 included U.S. Treasury Secretary Janet Yellen, California Gov. Gavin Newsom and former British Prime Minister Tony Blair. The topics were to include climate change, implementing artificial intelligence, health care accessibility, migration and economic justice.

In his opening talk, Pope Francis elaborated on the need to confront together the principal challenges facing society, particularly the "winds of war that blow across the world" and the climate crisis.

"It is time for the weapons to cease, for us to return to dialogue, to diplomacy. For the plans of conquest and military aggression to cease," he said. "That is why I repeat: No to war, no to war."

The pope also urged the leaders to "work together to stop ecological catastrophe before its too late," again sharing that he decided to write another document on the subject eight years after the publication of his encyclical "Laudato Si', On Care for Our Common Home." The document, which Pope Francis has said will be an apostolic exhortation, is expected to be released Oct. 4, the feast of St. Francis of Assisi.

The pope said that when people speak about migration, it is important to remember that they are not talking about numbers, but people.

"When we think of migration, let's think of the eyes of the children we find in refugee camps," he said.

He also recalled the work of the Vatican-owned Bambino Gesù pediatric hospital, where children from around the world are given free medical care -- including more than 2,000 Ukrainian children who fled their country will parents or relatives.

"It's evident that our great little hospital cannot solve the problems of sick children in the whole world," he said. "However, it wants to be a sign. A testimony of how it is possible, in the midst of so many efforts, to combine great scientific research aimed at curing children and the free welcome of those in need."

Clinton thanked the pope for his remarks and told him, "You make us all feel empowered, and perhaps that is your greatest power as the pope, that you make everybody -- even people who aren't members of the Roman Catholic Church -- feel that they have power and therefore responsibility."

Pope Francis closed by saying he was concerned about the situation of children worldwide and the fight against climate change. "Let us take action before it is too late," he repeated.

The pope met with Clinton and an 11-person delegation during a private audience July 5 in his residence, the Domus Sanctae Marthae. Vatican News reported at the time that the meeting "was held in private" and did not provide the names of those in the delegation, however, it said "the topic discussed was peace."