The 29-year-old Begin Again actress visited the post-conflict country in an effort to bring attention to the plight of its people after civil war left them in desperate need of aid.
"I didn't cry when I was there," she told Britain's The Telegraph, welling up with tears during an interview. "What bloody right would I have to cry when the people I met, who were living in as near to hell as I can imagine, weren't crying?"
"I'd never been to a refugee camp before, but I'd seen images. I read newspapers, so I know what goes on in the world, don't I?" she added. "But I'd never been in a post‑conflict zone, I'd never experienced the incredible, palpable atmosphere of terror or smelled the breathtaking stench of sewage from tens of thousands of people crammed together, with nowhere to go and nothing to do but wait."
"We look at people in faraway countries, on television and we can't quite believe they are the same as us, but they are," Knightley said. "They love their children as we do, they want an education for them, they want to give them a secure home and the freedom to run about in safety. Instead, they watch, powerless, as their toddlers play by the sewage -- there's nowhere else for them."