Angelina Jolie adopted her son, Maddox, in 2002

The actress, 30, has already adopted two children - Maddox, 4, from Cambodia and 16-month-old Zahara from Ethiopia.

Their surnames were legally changed to Jolie-Pitt after Jolie's partner, Hollywood star Brad Pitt, announced his intention to adopt them last year.

"Next, we'll adopt," she told US news network CNN. "We're looking at different countries".

The couple will make their decision on who to adopt based on "the balance of what would be best" for their current children, the actress said.

"It's, you know, another boy, another girl, which country, which race would fit best with the kids."

The interview will be shown on CNN on Tuesday, 20 June, as part of a day of programmes marking World Refugee Day.

Jolie has been a goodwill ambassador for the United Nations Refugee Agency (UNHCR) since 2001.