Steve Martin is to join the cast of 'Billy Lynn's Long Halftime Walk'.

The 'Cheaper By The Dozen' star is set to take a role in the adaptation of the novel of the same time.

Deadline reports that the 69-year-old actor and comedian will start shooting for the flick in April alongside Joe Alwyn.

Garrett Hedlund is also expected to take a key role in the movie.

The novel follows the story of 19-year-old private Billy Lynn, who returns to the United States from Iraq as one of a group of war heroes, following a particularly intense battle.

The heroic men are then sent on a 'victory tour' by the United States government but soon find out their heroic ending isn't all what it seemed as they are told they will have to return to war.

The film will be directed by Ang Lee, who has won the Academy Award for Best Director for 'Life Of Pi'.

He said previously: ''I am very excited to be going back to work and to be collaborating with my old friend Tom Rothman.

''The most important thing to me is storytelling and 'Billy Lynn's Long Halftime Walk' is a story that immediately gripped me. I look forward to starting the creative process with this extraordinary team of collaborators.''