"For Cleopatra, we've been working on it," Jolie told BBC radio. "There's been lots of different ideas of directors and a lot of different discussions. The script has been written by Eric Roth, who is a dear friend and a brilliant writer."
The actress said in an interview that playing the Egyptian pharaoh would be a great end to an actor's career.
Talking about the role, the 38-year-old said, "She's complicated, it's complicated to get this one right. She's complicated. But I think we're getting there. It's very close. So if we can pull it off...I imagine that the preparation for it is going to be big."
Hinting at retirement, Jolie said, "It's one of those [roles] you feel like maybe that's the one you put everything into and that's where you end it. That's where you finish, in a great way. You kind of go, 'What could you do beyond that one?' Put it all into that one."
Jolie previously revealed her intention to put her acting career to rest to focus on her humanitarian work and directing. She currently serves as the United Nations High Commissioner for Refugees campaigning against sexual violence in conflict.