Tom Hanks and Steven Spielberg "cast each other" for 'Saving Private Ryan'.

Tom Hanks

Tom Hanks

The pair have been close friends for many years and collaborated on a number of movies and mini-series, most recently the upcoming 'Bridge of Spies', but their friendship only turned into a professional relationship when they approached each other about working on 1998's 'Saving Private Ryan'.

Steven, who directed the movie, told TIME magazine: "It's funny because a couple of times it's been my idea, once it's been Tom's idea, and once it was that we decided independent of each other. Once Tom read the first draft of a script and I read the first draft of a script and we called each other on the phone at the same moment and decided to do it together - that was 'Saving Private Ryan'. That was the one time that he cast me and I cast him."

However, lead actor Tom admitted he did some research before approaching Steven, despite their friendship.

He said: "You're giving me a little too much credit. I wasn't quite that prescient. I think I did some ground work to find out if you were open to the phone call."