They hope to bring attention to the sexual violence and poverty in the Republic of Congo.
Cindy McCain and Affleck recently visited the Congo which is Africa's third largest country.
The actor also has a charity, the eastern Congo initiative.
The duo is calling for a special advisor to the region who can coordinate the efforts of governments and western aid organizations.
Tuesday, they both testified before congress.
"We strongly believe that if we continue to place Congo on the back burner of U.S. policies it will come back to haunt us. The federal budget may be a zero sum game. But our morality, our sense of decency, our compassion for our fellow human beings is not," Afleck said.
Since 1998, more than 5 million people have been killed in the Congo by violence, disease and poverty.
More than 1 million have been forced from their homes.