"This is a happy day because it is not often enough that these children are represented in this town," Jolie said to a room crowded with cameras and reporters.
Jolie appeared with four others to open the Washington headquarters of Global Action for Children, a nonpartisan advocacy group formed in 2003.
"I am not a policy expert. I am here to ask you to think about orphaned children not as a burden, but as an opportunity," Jolie said. "Their education and well-being is an investment in our future."
The group, supported by a collection of charities, religious groups and nongovernmental organizations, wants the Bush administration to commit an additional $2.5 billion a year to education and to aiding orphans in developing countries.
"The crisis has far outpaced the funding," said Jennifer Delaney, the group's executive director.
Photos: Angelina Jolie: Viet Mom
Jolie said orphan children sometimes beat the odds and survive but often are enslaved, resort to prostitution or are forced to become child soldiers.
"Our government has the power to choose which path these children are going to take," Jolie told reporters at the National Press Club. "We know the consequences of our inaction."
Jolie has adopted three orphan children, but said any help that people in the United States can offer is better than nothing. "The best solution for anyone who is abandoned or displaced is to be home (in their own countries)," Jolie said. "I would support that first and foremost."
"I'm so lucky to have the opportunity to know these children," Jolie said of her own brood. "I feel fortunate to have orphan children in my home."
Jolie said there are ways that young people can get involved in this cause. "Educate themselves and know the power of their voice," she said.
Jolie demurred when asked if her cause might be better served if she became more political or ran for elective office. "I certainly don't think anybody wants that," she said, laughing.