Jolie and Warren joined other advocates last Thursday in the US to launch the Global Action for Children - a campaign to increase US government funding by $2.5bn per year to provide free primary school education in developing countries.
Among the members of the organisation are the United Methodist Board of Church and Society, a founding member, and the Evangelical Lutheran Church in America.
Jennifer Delaney, GAC executive director said that about 20 million children will lose at least one parent to HIV/AIDS by 2010, and millions more will be orphaned by tuberculosis, malaria and war or have parents who are sick and dying, according to the United Methodist News Service.
"I read a startling statistic that 12 million children are orphans, and I couldn't believe I didn't know any of them," said Warren at the news conference, reported UMNS.
The executive director of Saddleback Church and wife of "Purpose Driven" Pastor Rick Warren said that the AIDS-affected women whom she spoke with had repeatedly asked her one question.
"The one refrain I kept hearing from the mothers was 'Who will take care for my children?' I had to say, 'I will take care of the children," said Warren.
Prior to the press conference, GAC's Delaney and Jolie, who serves as the honorary chairperson of the GAC board, met with senior officials at the US Department of State to discuss policies and funding that will support OVC programmes and access to education.
"I am no policy expert," Jolie said, "but I know the price of inaction and indifference. We need people to think about orphans not as a burden but as a great opportunity."
The GAC was formed in 2003 as a campaign organised by faith-based, non-governmental and student organisations concerned about orphans and vulnerable children and the communities that care for them.
Others at the launch event included the Rev Mpho A Tutu, an Episcopal priest and founder and executive director of the Tutu Institute for Prayer and Pilgrimage; and Gene B. Sperling, senior fellow at the Center for American Progress.
Last week's news conference marked the establishment of GAC's new headquarters in Washington and formalisation of the organisation and staffing. It was also held as part of Global Education Awareness Week.