The man who knows how it all ends reveals how he plans to end Game of Thrones

George R. R. Martin has admitted there "may be changes" to the TV ending of 'Game of Thrones' compared with his plans for the books.

The 70-year-old author began writing his 'A Song of Fire and Ice' series in 1991, long before the HBO fantasy drama based on the saga began production, but he has been working on sixth book 'The Winds of Winter' - the follow-up to 2011's 'A Dance with Dragons' - for several years, meaning the programme has now forged its own path.

While George confirmed show runners David Benioff and D.B. Weiss have taken the "major points" of his planned ending for the saga, the upcoming eighth season will still have significant differences to what he has mapped out for his remaining novels.

He told Rolling Stone magazine: "I've been so slow with these books. The major points of the ending will be things I told them five or six years ago. But there may also be changes, and there'll be a lot added."

Meanwhile, though Benioff and Weiss have stayed tight-lipped on the ending to the show, they opened up about their favourite ever TV series finales.

They said in a joint email interview with the publication: "'Breaking Bad' stuck the landing. We always talk about the 'Sopranos' ending -- as controversial as it may have been at the time, it's hard to imagine a better ending for that show, or any show."

George recently revealed he has been so busy working on the sixth book in the series that he had to turn down a cameo appearance in the final season of the TV show, which is set to air next month.

He said: "[Show runners David Benioff and Dan Weiss] invited me to a cameo in one of the final episodes, which I was tempted to do.

"But I didn't think just for the sake of a cameo I could take the time to return to Belfast."