"It is a campaign of murder, and fear, and displacement and starvation," he said.
He not only asked senate leaders to take action, but he also explained how gas prices are being affected by the violence.
Showing senators a video he shot while on his trip, Clooney spoke about the repeated bombings of residents in the Nuba Mountains, an area between Sudan and the recently formed South Sudan.
The Oscar winner stood over dead bodies, and even discovered old bombs. He said the same government that committed the atrocities in Darfur is trying to ethnically cleanse the region.
"Three days ago while we were in the Nuban Mountains, 15 bombs were dropped on a neighboring village. When we got there, we found children filled with shrapnel, including a 9-year-old boy who had both of his hands blown off," Clooney said.
It's not the first time Clooney has lent his star power to the cause. But this time he tried to get the average American to relate by showing how violence in South Sudan directly affects gas prices around the world.
"So six weeks ago, the south shut down their oil production, it just stopped. And overnight China lost six percent of its overall oil imports, which means they have to go elsewhere and that raises the price of oil," Clooney said.
Clooney did keep his tone serious, all the while maintaining his jokester image.
"I know this: if we work together, all of us, we can't fail. And that last part is just opinion," he said.
The Sudanese government has denied these accusations in the past. Clooney did offer senators suggestions on how to help, like freezing offshore bank accounts of war criminals, toughening sanctions and increasing diplomacy with China to stop the violence. The actor is planning to meet with Secretary of State Hillary Clinton and President Obama on Thursday.