The 38-year-old actress revealed that many different directors have been suggested for the project, with previous frontrunner Ang Lee seemingly busy on a different project, reported BBC online.
"We've been working on it. There's been lots of different ideas of directors and lots of different discussions. The script has been written by Eric Roth, who is a dear friend and a brilliant writer," Jolie said.
However, the 'Maleficent' star said that Cleopatra is a "complicated" character to portray, adding that she will have to prepare herself for the role.
"She's complicated, it's complicated to get this one right. I think we're getting there. It's getting close. I imagine the preparation for it is going to be big."
Jolie even suggested that playing Cleopatra would be such a career-defining moment that there would be no need to continue acting.
"It's one of those that you think 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! What could you do beyond that one" the actress said.