Author George R.R. Martin has been asked time and again when the sixth book in his "A Song of Ice and Fire" series will come out, as it has been pointed out that "Game of Thrones" is going to overtake the novels when its sixth season is shown on HBO. But Martin said that he's not worried about it, pointing out that the show is indeed progressing at a fast pace. 

"The show is moving forward like a locomotive, or sometimes a jet locomotive," the author told Geekwire at the Sasquan Science Fiction Convention in Spokane. "They're writing 60-page scripts; I'm writing 1,500 page novels." 

Martin admitted that there was a time when he was worried about the show overtaking the novels, but now, he's not that concerned anymore. 

"Worrying about it isn't going to change it one way or another. I still sit down at the typewriter, and I have to write the next scene," he said. 

Previously, Martin has been criticized for doing a lot of public appearances instead of writing "The Winds of Winter." But last year, Martin wrote on his blog, Not A Blog, that he has cut down on appearances as he fully intends to work on the novel. Earlier this year, he told Entertainment Weekly that finishing the sixth book before season 6 of "Game of Thrones" airs next year "has been important to me all along." 

Although Martin thinks that he is being overly optimistic as to how quickly he can finish the book, he said that he has cancelled convention appearances and even turned down interviews so he can get to work. He has also bowed out of writing episodes for the HBO series for the upcoming season. 

"There are a lot of talented people working on the TV show, a lot of very talented people. But I am the only one that can do the books," Martin told NewYorkJets.com.