Martin discussed why he hasn't finished the book in a lengthy blog post titled "Last Year (Winds of Winter)."
"'The Winds of Winter' is not finished," he wrote. "Believe me, it gave me no pleasure to type those words. You're disappointed, and you're not alone. My editors and publishers are disappointed, HBO is disappointed, my agents and foreign publishers and translators are disappointed ... but no one could possibly be more disappointed than me."
Martin said he wanted the book to be completed last year so it could be released before the April premiere of the sixth season of HBO's television adaptation of the hit book series. Still, after several deadline delays thanks to travel and appearances, Martin said there's still much work to be done.
"I am months away still ... and that's if the writing goes well," he wrote. "(Sometimes it does. Sometimes it doesn't.) Chapters still to write, of course ... but also rewriting. I always do a lot of rewriting, sometimes just polishing, sometimes pretty major restructures."
Martin, 67, said missing his deadline didn't come as a surprise to him.
"Look, I have always had problems with deadlines," he said. "For whatever reason, I don't respond well to them. ... I wrote my first novel, 'Dying of the Light,' without a contract and without a deadline. No one even knew I was writing a novel until I sent the completed book to Kirby to sell. I wrote 'Fevre Dream' the same way. I wrote 'The Armageddon Rag' the same way. No contracts, no deadlines, no one waiting. Write at my own pace and deliver when I'm done. That's really how I am most comfortable, even now."
Martin concluded the blog post by saying, "Meanwhile, I'll keep writing. Chapter at a time. Page at a time. Word at a time. That's all I know how to do."
Many fans complained about the fact that Martin wasn't done while others applauded his honesty. Hours later, Martin responded with a second blog post titled, "Thanks."
"The outpouring of support in response to my post on 'The Winds of Winter' has been astonishing. Thank you all, so very much," he wrote Saturday evening. "But I cannot tell you how much I appreciate all the kind words and good wishes."