Takarada, 80, starred in the 1954 original movie of the same name, as well as several other films about the colossal monster.
Edwards' version of the story follows a father and son, played by Bryan Cranston and Aaron Taylor-Johnson, who try to figure out what the city-stomping creature is and how to stop it.
"When you make a film, there are many, many scenes and a lot of my favorite little ideas or shots are not in the movie because you have got to think of it as a whole," Edwards told reporters at a recent roundtable interview in New York.
"From an emotional point of view, in terms of my love of Godzilla, the hardest thing was Akira Takarada. He was in the original films and did a cameo for us on Day 1. And it felt very appropriate at the time because he played an immigrations officer who welcomes Aaron Taylor-Johnson's character to Japan. So, it was like this perfect Day 1, first shot and then when we constructed the film... Basically, there was a lot of pressure to get on with the adventure and get to the monsters as soon as you can and so lots of things came out of that part of the movie and I hung onto that until the last second and it was still deemed by the screenings -- when we tested it -- that we had to get it shorter and, so, that ended up having to go, which is probably my biggest regret."
Edwards said he wrote to Takarada to explain the change.
"He's a real gentleman, so I think he was understanding. But it's one of those horrible things about the process," the director said.
Co-starring Ken Watanabe, Juliette Binoche, Sally Hawkins and Elizabeth Olsen,Godzilla is in U.S. theaters now.