Religious leaders from a half-dozen faiths have signed on to a new Vatican initiative to end modern-day slavery by 2020, declaring that human trafficking, forced labor and prostitution are crimes against humanity.

Pope Francis and the Anglican archbishop of Canterbury, Justin Welby, were joined Tuesday by the Hindu guru Mata Amritanandamayi, known as Amma, as well as Buddhist, Jewish and Shiite and Sunni Muslim representatives for a signing ceremony of a joint declaration against modern slavery.

The declaration commits the signatories to do everything in their power and within their faith communities to work to free the estimated 35 million people enslaved across the world by 2020.