Angelina Jolie says her work as a humanitarian ambassador for the United Nations at first left her tearful and overwhelmed.

"The first two years I just cried constantly," the actress told Newsweek. "I couldn't really talk about the situation without being emotional. And I went through a period of just complete lack of hope."

During her February visit to the Oure Cassoni camp on the border between Darfur and Chad she came across a disturbed 7-year-old boy whose family had tied him to a pole to stop him wandering away or banging himself. The boy had spent 48 hours hiding in the bush after his village was bombed.

"I talked to him for like half an hour and just kind of looked at him for a long time before he touched me," Jolie told the magazine, "and there was a little boy in there who was open to a kind sound."

Jolie has visited camps in Africa, Pakistan and Cambodia as part of her work as a goodwill ambassador for the United Nations High Commissioner for Refugees. She said she travels unaccompanied on commercial flights, and doesn't care about people who describe what she does as celebrity tourism.

"I don't know if anybody saying that has spent the last six years of their life going to over 30 camps and really spending time with these people," said Jolie, who wants to return to Cambodia.