Cara Delevingne has been cast in the Luc Besson-directed 'Valerian and the City of a Thousand Planets'.

The 22-year-old model-turned-actress, who recently starred in 'The Face Of An Angel', is set to appear alongside American actor Dane DeHaan in an adaptation of the French comic book series 'Valerian and Laureline'.

Luc, who directed the 1997 blockbuster 'The Fifth Element', tweeted: ''My first tweet ever! Let's share a real news! My next film is a big sci-fi: #Valerian and the City of a Thousand Planets.''

His message was soon retweeted by Cara, who's been cast as 11th century peasant girl Laureline in the story about time travel.

Cara's casting comes shortly after she revealed that she much prefers acting to modelling, even though she made her name as a catwalk star.

The London-born beauty said: ''I've always wanted to be an actress, more than anything in the world.''

Even though she's walked for a number of top fashion brands, Cara confessed it fails to ignite her ''fire''.

She said: ''Modelling was never a passion of mine. It wasn't something that made my heart beat and built a fire inside of me.''