Dan Steinberg / Invision/AP 1 / 6
Dan Steinberg / Invision/AP 1 / 6

CAIRO (AP) -- Actress Lucy Liu, who has produced a film about children sold into the sex trade in Cambodia, says the fight against human trafficking will be long.

Liu praised several projects funded by the U.N. children's agency in Egypt, where she was promoting the film "Red Light" at the Cairo International Film Festival.

The actress co-produced and narrated the movie, which follows the stories of a number of girls over the course of four years as they are kidnapped and sold to brothels in Cambodia.

Liu said Wednesday it "is really going to take a really long time" to fight human trafficking, labeled the third most profitable business in the world after weapons and drugs trading.

That assessment rings true in the Middle East, where stigma in conservative societies and a lack of data have frustrated activists' efforts. Highlighting those challenges, organizers of several UNICEF-funded programs Liu visited in Egypt did not even want to make details of their efforts public out of fear doing so would stir up controversy and pressure from conservatives.

"The first step is there are a couple of projects that exist and that is something wonderful," Liu said.

In Egypt, the sex trade is often hidden under the guise of temporary marriages sanctioned by some religious figures and local authorities. Under these marriages, hundreds of underage girls in rural Egypt are essentially sold by their families for large sums to wealthy visitors from Gulf nations.

Egypt recently passed its first child protection law, which criminalized trafficking and raised the age of marriage to 18.

The country's first Lady, Suzanne Mubarak, launched a global initiative to fight human trafficking in 2006, signaling that there is a political will to confront an issue affecting nearly 2.4 million people around the world, according to 2007 figures from the U.N. International Labor Organization.