ROME — Declaring that human trafficking is “a crime against humanity,” Pope Francis and the leaders of other major faiths across the globe vowed Tuesday to work to eradicate slavery by 2020.

“In the eyes of God, each human being is a free person, whether girl, boy, woman, or man, and is destined to exist for the good of all in equality and fraternity,” says the declaration signed by Anglican, Orthodox, Hindu, Buddhist, Jewish, and Muslim leaders during a ceremony at the Vatican.

The meeting was sponsored by the Global Freedom Network, a faith-based network that Francis launched earlier this year with Archbishop Justin Welby of Canterbury, the leader of the 80 million-strong Anglican Communion, and Ahmed Muhammad Ahmed el-Tayeb, Grand Imam of Al Azhar Mosque in Egypt, considered the Vatican of the Sunni Muslim world.

Among the signatories to the document were two rabbis, an imam and a sheikh, two ayatollahs, a Hindu guru, a Zen master, and an Orthodox patriarch. In all, eight different religions or Christian churches were represented.

In his brief remarks, Francis said that “any discriminating relationship that doesn’t respect the fundamental condition that the other is my equal constitutes a crime. An abhorrent crime against humanity.”

“We [the signers] make this declaration in the name of the victims,” said Francis, who pointed out that human trafficking occurs virtually everywhere, from slums to the world’s wealthiest cities, hidden behind closed doors or in plain sight on streets where women are forced into prostitution.

The declaration underlines that modern slavery – in the form of human trafficking, forced labor, and prostitution, as well as organ mutilation and trafficking – is a crime against humanity.

The signers, gathered on the UN-declared International Day for the Abolition of Slavery, pledged to do everything in their power and to work together for the freedom of all those who are enslaved and trafficked.

“Today we have the opportunity, awareness, wisdom, innovation, and technology to achieve this human and moral imperative,” the declaration reads.

Leaders from a variety of international organizations, social groups, and businesses witnessed the signing of the declaration. They included the Walk Free Foundation, a partner of the Global Freedom Network, founded by Australian philanthropist and mining magnate Andrew Forrest.

Melissa Rogers, head of the White House Office of Faith-Based and Neighborhood Partnerships, said the Obama administration supported the Global Freedom Network. “The way we will end this is by joining hands and working together,” she said. “That’s what this day is about, across faiths, backgrounds, and beliefs, and that’s where our hope lies.”

The fight against modern slavery was one of the issues Pope Francis and Barack Obama discussed when the US president visited the pontiff last March.

UN secretary-general Ban Ki-Moon sent a message to the meeting that included a reminder that no society is immune to this problem: The UN has identified at least 152 countries of origin and 124 countries of destination for trafficking; one in three victims is a child.

Zen Master Thich Nhat Hanh, represented by his eldest monastic student, called for including spiritual action in the fight. “Contemplation must be accompanied by action.”

“The roots of human trafficking run deep, and we can’t fight it as lonely warriors,” he said. “This is why we need to build a community to protect human life.”

The Global Freedom Network aims to combat human trafficking, which it says is the 21st- century version of slavery. This illegal industry is estimated to involve 36 million people, and according to the International Labor Organization, generates $150 billion in annual revenue.

The interreligious anti-slavery network outlined several fields of action: Mobilizing faith-based communities, checking supply chains to promote ethical purchasing arrangements, improving care for victims and survivors, advocating for legal reforms and aggressive law enforcement, and providing money to carry out these goals.

For Pope Francis, who has made the fight against human trafficking a priority of his papacy, this commitment is nothing new.

As archbishop of Buenos Aires, then-Cardinal Jorge Mario Bergoglio sponsored a non-governmental organization called “La Alameda” that fed him information about slave labor and prostitution in Argentina; he then found work and asylum for survivors.

During a Mass in a Buenos Aires train station in 2012, he compared the city to a “butcher shop” that takes away the human dignity of people trapped by these networks.

Addressing a Vatican-organized youth symposium against prostitution and human trafficking in November, Francis appealed for a committed fight against modern slavery, saying that simply supporting the cause “is not enough for a Christian.”