Pope Francis urged people worldwide "not to turn away from the sufferings of our brothers and sisters, our fellow human beings, who are deprived of their freedom and dignity."
Young Africans are being seduced into modern slavery by the promise of a dream that never comes true, an English cardinal told a conference on human trafficking.
Cardinal Vincent Nichols of Westminster said "there seems to be no enticement that isn't being used" by human traffickers to entrap children.
Tens of millions of people are "in chains" because of human trafficking and forced labor, and it leading to their "dehumanization and humiliation," the pope said.
Millions of the world's children today are victims of armed conflict, pornography and sexual trafficking, and still more "are denied the most fundamental right to life," said the Vatican's nuncio to the United Nations.
"Prenatal selection eliminates babies suspected to have disabilities and female children simply because of their sex," Archbishop Berardito Auza said Oct. 17 in a statement to the U.N. Social, Humanitarian and Cultural Committee, which was discussing the rights of children.
He is the Vatican's permanent representative at the U.N. in New York.
Pope Francis called for the "globalization of charity" through an international network to fight human trafficking and ensure the rights of migrants and refugees.
The pope's words appeared in his annual message for the World Day of Migrants and Refugees, which in 2015 will be observed Jan. 18. On Tuesday, the Vatican released the pope's message, "Church Without Frontiers, Mother to All."
Human trafficking destroys the lives of millions of children, women and men each year, making it a real threat to peace, the Vatican said as it announced Pope Francis' 2015 World Peace Day message would focus on the phenomenon.
"Slaves no more, but brothers and sisters" will be the theme for the Jan. 1, 2015, commemoration and for the message Pope Francis will write for the occasion, according to the Pontifical Council for Justice and Peace.
Pope Francis denounced those responsible for human trafficking, slave labor and arms manufacturing, saying people producing weapons of war are "merchants of death."
"One day everything comes to an end and they will be held accountable to God," the pope said at his weekly general audience Wednesday.
The pope also launched an appeal to the international community to help safeguard children from forced labor, highlighting the plight of an estimated 160 million child workers worldwide.
During the World Cup in Brazil, a nationwide campaign will raise awareness of the hundreds of vulnerable children at risk of sexual exploitation.
Pope's quotes: Some of our favorite quotes from Pope Francis
Four women who were forced into sex slavery and later freed met Thursday with Pope Francis at an international conference on human trafficking held at the Vatican to combat what the pontiff called a "crime against humanity."
After a private meeting with the victims, the pope joined church officials and police chiefs from 20 countries, including the U.S., England, Thailand and Nigeria, in an effort to build global cooperation to fight the problem.