Affleck, who founded the nonprofit Eastern Congo Initiative and has previously testified before Congress on Congolese refugee camps, joins Clinton and U.S. Agency for International Development (USAID) Administrator Rajiv Shah at the USAID Child Survival Call to Action forum in Washington, D.C. on Thursday.

The forum represents a movement to end preventable child deaths in places like the Congo.

“Timing feels right to bring awareness to what's happening in the #Congo today & to share my stories from this part of the world,” Affleck wrote in his first tweet, sent Wednesday.