James Gunn is ''terrified'' about the upcoming release of 'Guardians of the Galaxy'.

The 43-year-old director of the Marvel Comics film has admitted he's nervous about finally finishing the production and seeing it enter cinemas on August 1 as he's spent every waking moment working on the project for the last two years.

In a message posted on his Facebook page, Gunn said: ''This is essentially my last week of actually making Guardians of the Galaxy.

''It's been two years straight and I've starting to become terrified of actually having to STOP.''

Gunn also wrote the script for the film - which expands the Marvel universe into the cosmos, where adventurer Peter Quill (Chris Pratt) finds himself the object of a bounty hunt after stealing a mysterious orb - and he's confessed he'll be emotional to say goodbye to the cast and crew when production comes to an end.

He explained: ''I'm starting to get very sad every time I think of how I'm going to miss all of the people I've been working with side-by-side for the past two years.''

Pratt will be joined by fellow actors Bradley Cooper, Zoe Saldana, Vin Diesel, Karen Gillan and Benicio Del Toro in 'Guardians of the Galaxy, and Gunn has revealed that he could be planning a sequel.

He added: ''I swear, I've gotten angry with filmmakers like Ridley Scott and George Lucas who can't let go of their old films and want to keep going back and offering up different versions, but I can easily see myself doing that now.''