Bradley Cooper is "grateful for" The Hangover franchise.

The 38-year-old actor - who plays Phil Wenneck in the movie series - will miss working with co-stars Zach Galifianakis, Justin Bartha and Ed Helms and director Todd Phillips but says he is happy they were able to complete the trilogy.

"The good thing is, we got three movies out of it. That's the icing on the cake. It's sad. We're all pretty grateful. The third one, we were conscious of the fact it's rare that a comedy series gets three movies. I miss working with them. Hopefully they'll be in my life for a long time. I loved Phil. I love that character. I feel a state of gratitude. When we made the first movie, we had no idea that there'd be another two, so this is all kind of a bonus. "

The film sees the Wolfpack gang - comprised of Bradley, Zach, Justin and Ed - head back to Vegas to settle one final debt and The Hangover and The Hangover Part III co-star Heather Graham revealed she was thrilled to become an "honorary Wolfpack member." She said, "It's really fun to be around so many talented, cute men. They're so funny. I loved it. I was told I was an honorary Wolfpack member, so I felt very happy about that."