Damon discussed his and Krasinski's creative process while collaborating on Promised Land in an interview with Flicks and Bits.
"John has got this incredibly fast brain. So the writing would come quickly and we would laugh together," he recalled. "It reminded me of writing with Ben Affleck, a very similar feeling and above all else a lot of fun - I'd forgotten just how much."
The Oscar winner continued: "During the week, John and I would go back to our jobs and pore over what we'd written during our down-times, scribbling notes and ideas before reconvening on the weekend to revise and revise and revise.
"My wife said to me, 'You had such a great time that even if it never gets made, it was worth it because you remembered how much you love writing and you had this incredible creative experience with John'. It was a lot of fun writing with John."
Promised Land is the story of corporate representative (Damon) whose efforts to buy drilling rights are opposed by a community organizer (Krasinski).
The film opens on December 28 in limited release in the US and hits UK cinemas on April 19, 2013.
Watch a trailer for Promised Land below: