The 68-year-old has confirmed he simply doesn't have time to watch the blockbuster HBO series because he is too busy touring and trying to finish his latest novel.

The Winds of Winter, the sixth and second-last book in Martin's epic fantasy series, was expected to hit bookshelves this year but has been pushed back to at least 2018.

But Martin isn't concerned about missing his weekly sit-down with HBO. In fact, he told Metro taking a break from the TV adaption has been a blessing, because he can pour more of his limited time and energy into his literary universe as opposed to the one starring Kit Harrington and Emilia Clarke.

"The book series and TV adaption go their separate ways," he said. "On the screen, characters are killed right and left. About twenty of them have died already, which are quite alive to me and will appear in a new book."

While the author admitted growing older hasn't added any "enthusiasm" for the series, he did push back against suggestions he was writing The Winds of Winter slower than his previous books.

"I did not start to write slower over the years," he said. "I was working on the first book for six years, and four on the second one. Fantasists who release their novels every year do not offer books of large volume. These are not 1500 pages like mine, but, for example, 500."

Martin recently returned to his home in the US after touring Finland and Russia. He has promised to keep working away on The Winds of Winter, but has also hinted that there are now five potential Game of Thrones successor shows in the works that could eat up his spare time.

The finale for Game of Thrones' season seven shows in Australia on Monday.