Goodwill ambassador for the United Nations Angelina Jolie was on a humanitarian trip to Baghdad Thursday, to learn more about the situation of millions of Iraqi refugees and to draw attention to their needs.

The 32-year-old goodwill ambassador for the United Nations High Commissioner for Refugees mingled with American troops at a US military base in the high-security Green Zone in central Baghdad and met with Gen. David Petraeus, the top U.S. commander in Iraq, and Iraqi Prime Minister Nouri al-Maliki, says the American Embassy, the Associated Press reports.

Jolie was on a US government mission with the State Department to Iraq, accompanying under secretary of State Paula Dobriansky “to learn more about the humanitarian crisis and the 4 million displaced people, 58 percent of whom are under 12,” her philanthropic adviser, Trevor Neilson, was quoted by People.com as saying.

“There's lots of goodwill and lots of discussion, but there seems to be just a lot of talk at the moment, and a lot of pieces that need to be put together. I'm trying to figure out what they are,” Jolie told CNN during an exclusive interview.

“What happens in Iraq and how Iraq settles in the years to come is going to affect the entire Middle East,” she said. “And a big part of what it's going to affect, how it settles, is how these people are returned and settled into their homes and their community and brought back together and whether they can live together and what their communities look like.”

Thursday afternoon, Jolie visited internally displaced people. The actress returned to the U.S. Thursday night.

More than 4.2 million Iraqis have fled their homes in the war-torn country, around 2 million to neighboring states, mostly Syria and Jordan; another 2.2 million are displaced inside Iraq, CNN reports. Of the internally displaced, 58 percent are under age 12.