Steve Zahn has joined the cast of 'War for the Planet of the Apes'.

The 'Joy Ride' actor is to play a new ape character in the upcoming third instalment of the rebooted film series for 20th Century Fox, according to Deadline.

However, details of his character and of the movie's plot are currently being kept under wraps following the release of 'Dawn of the Planet of the Apes' last year and 'The Rise of the Planet of the Apes' in 2011.

Zahn will join returning cast members Andy Serkis - who plays leader of the apes Caesar - and Gabriel Chavarria and Woody Harrelson.

Director Matt Reeves is also returning to the helm after co-writing the film with Matt Bomback.

Zahn's most recent projects include a recurring role as the Dunphy family's annoying neighbour Ronnie in 'Modern Family' and as former professor and human behaviourist in the US TV series 'Mind Games'.

The 47-year-old actor will next appear in 'Captain Fantastic' and recently wrapped on films 'The Ridiculous 6' and 'Robodog'.