Speaking before thousands gathered in Havana, Pope Francis begged Colombia's government and largest guerrilla army to end South America's longest-running conflict, saying they cannot allow another failure to derail peace efforts.
Francis issued the appeal Sunday from Revolution Plaza in Havana, where peace talks underway for more than two years between the Revolutionary Armed Forces of Colombia and representatives of Bogota aim to end a half-century of fighting.
He said: "May the blood shed by thousands of innocent people during long decades of armed conflict" sustain efforts to find a definitive peace.
Francis added: "Please, we do not have the right to allow ourselves yet another failure on this path of peace and reconciliation."
Earlier in his speech, the Pope urged Cubans to look out for one another and not just judge others based on what they are or are not doing. He told them that those who want to be great must serve others, and not be served by them. He said Cubans should avoid "judgmental looks."
He said "All of us are asked, indeed urged, by Jesus to care for one another out of love ... Without looking to one side or the other to see what our neighbor is doing or not doing."
It wasn't immediately clear what Francis was referring to. But many Cubans complain about the rigidity of a system in which virtually every aspect of life is controlled by the government, from cultural institutions to block-level neighborhood watch committees, in which people are excluded or lose benefits if they are perceived as being disloyal or unfaithful to the principles of the revolution.
That has eased in recent years, but it remains a problem in the eyes of many islanders and outside observers.
Many Cubans are also increasingly concerned about growing inequality, as those with access to foreign capital live better than others who struggle to feed themselves, generating jealousy and division within families and society at large.
The church's first Latin American pope recently helped nudge forward the historic reconciliation between the United States and Cuba with a personal appeal to the leaders of both countries.