Julianne Hough and Josh Duhamel had "amazing chemistry" in the film version of his book Safe Haven, writer Nicholas Sparks has said.
The Rock Of Ages actress and the Transformers actor star opposite each other as a woman fleeing a dark past and the new man she falls for in the romantic film, and Nicholas said both did justice to his characters.
He said: "For the most part, the cast in any of my films have essentially chosen themselves for the roles. We look for great performance ability, but also chemistry, and Josh and Julianne had amazing chemistry from the beginning.
"I thought they both did a terrific job."
The Notebook author said he was delighted the movie, directed by Lasse Hallstrom, was so well received when it opened earlier this year.
"For this novel, I wanted to introduce the theme of danger and a growing sense of intensity that rises - and surprises - until the very end. I wanted the same kind of feeling in the film, and I couldn't be any happier. The cast was terrific and the director was amazing, and I was thrilled that audiences loved it," he said.
Another of Nicholas' books, The Best Of Me, is also set to get the big screen treatment.
He said: "I am hopeful that The Best Of Me will start filming this year. We have started the casting process, but I don't want to give too much away."
: Safe Haven is out now on Blu-Ray and DVD.