He basically was just there to tell the American's what Godzilla was about, lol. He served little actual purpose, but I enjoyed him anyway, especially with lines like this: "No matter what happens, Godzilla will live."
I just thought the Burr addition was a nice touch. Since Return of Godzilla was a sequel to Gojira, Godzilla 85 was a sequel to Godzilla: King of the Monsters. Burr's contribution to the film was definitely just telling American's what Godzilla was really about, but it was something that was needed considering most American's only knew Godzilla as the cuddly monster who fought other monsters and teamed with Jet Jaguar.