Director George Lucas says it took 20 years to get his latest film made, "because it's an all-black movie".

Speaking on The Daily Show, Lucas said he had to self-fund Red Tails, the true story of a group of African-American pilots who fought in World War II.

Lucas put $58 million (37.8 million) of his own money into the movie. It will be released by his company Lucasfilm, and distributed by Twentieth Century Fox.

He is putting a further $35 million (£22.8 million) towards the distribution costs, said trade paper The Hollywood Reporter.

If his film does well at the box office, Lucas said he had a prequel and sequel planned.