Cindy McCain and Ben Affleck join forces to help Congo

Washington (CNN) - Hollywood celebrity Ben Affleck is bringing his star power to Capitol Hill Tuesday, and teaming up with an unlikely partner –Cindy McCain, wife of Arizona Republican Sen. John McCain– to bring attention to the humanitarian crisis in eastern Congo.

ABC News reports that Affleck and McCain will appear on Tuesday before the House Africa, Global Health and Human Rights Subcommittee at a panel held by Republican Congressman Chris Smith of New Jersey. Affleck said last week that he will speak alongside representatives from the State Department, USAID, and other human rights groups to "bring increased investment and attention from both the public and private sectors to the devastating humanitarian crisis in eastern Congo."

"When you look at this place where 3 million people died over the last 15 years, that is a humanitarian catastrophe," Affleck told ABC News' Jake Tapper on Monday.

"People are dying, really dying and have been for a long time. I don't know that I can make any more argument about why you should pay attention to this. At a certain point, you know, it just seems morally self evident," Affleck said.

During the interview, McCain acknowledged that she and Affleck make an unlikely pair.

"It is an odd couple relationship, I've had other people say that to me." Cindy McCain told ABC News' Jake Tapper, of her decision to work with Affleck, who recruited McCain on behalf of the Eastern Congo Initiative, a non-profit organization that he founded in 2010.

McCain went on to explain her initial skepticism, saying her experience with celebrity activists, "had not been good. It hadn't been heartfelt." But, McCain said, "Ben has a working knowledge of this region. He not only understands the issues, but he understands what we need to be doing."

Last fall the Oscar-winning-screenwriter hosted a bi-partisan panel discussion on U.S. foreign policy in the Democratic Republic of the Congo featuring Massachusetts Democratic Sen. John Kerry and GOP Sen. John Boozman of Arkansas.

He launched ECI in 2010 to provide support for Congolese community organizations working to rebuild the war-ravaged country. "The people of eastern Congo are remarkably resilient and Congressman Smith's leadership is helping the Congolese rise above their troubled past," he said.

Affleck isn't new to the political arena: he previously testified before Senate Appropriations Subcommittee on Health and Human Services in July of 2001 to support funding for stem cell research at a hearing titled "The Promise of the Genomic Revolution," and in 2008 he met then-Speaker Nancy Pelosi after observing House floor proceedings as he researched his role in "State of Play," a political drama set in Washington, D.C.

- CNN's Deirdre Walsh contributed to this report.