The actor spoke about the actress, 22, in an article for the Huffington Post in which he analyzed her latest movie 'Snow White And The Huntsman."
He said: "Some might argue that Stewart - or any young upstart buoyed by the surge of a successful franchise, album, or Internet meme - is just as unjustly charmed. Some could say she had a lucky break when she was cast in 'Twilight' and then rose to international stardom based less on her own skills than on the success of the project.
"But, whereas Snow White would more than likely be inarticulate, diseased and frail after being confined in a tower for 10 years, Kristen Stewart landed 'Twilight' after years of working with some of the best directors in the business (David Fincher, Sean Penn). She actually does deserve the crown."
He added: "To me, then, the images of Snow White as a leader of immense strength, charging on horseback across the beach at the head of an army, has less to do with her character and more to do with the actress who plays her.
"Stewart has braved more scrutiny of her private life than most presidents. She has taken big career risks by doing films like 'Welcome to the Rileys', 'The Runaways' and 'On the Road' (nudity, I hear). She has worked her ass off. Whatever Snow White may be, Kristen is a warrior queen. Give her the crown."