George R.R. Martin won't get involved in 'Game of Thrones' spin-offs until he has finished next book

Game of Thrones creator George R.R. Martin has promised not to get involved in writing scripts for the upcoming TV spin-offs until he has finished work on the long-delayed sixth novel The Winds of Winter.

In a blog post on his official website, the 71-year-old writer pledged to keep his focus on the next novel in his A Song of Ice and Fire series, which has been repeatedly pushed back due to Martin’s slow writing pace and busy schedule.

Read more: Martin says Thrones could’ve gone for five more seasons

The Winds of Winter, which will be the penultimate book in the series, was originally due to be published in 2016, prior to the sixth season of Game of Thrones.

Martin has since failed to meet numerous deadlines to deliver the manuscript, with no end currently in sight.

HBO has now confirmed a new 10-episode spin-off entitled House of the Dragon, focusing on the Targaryen dynasty, and Martin said he “expects to be involved” in some respect.

He has moved quickly, however, to reassure fans that his focus remains on delivering the next novel.

Read more: Martin says TV show slowed down his writing

“Let me make this perfectly clear,” he wrote, “I am not taking on any scripts until I have finished and delivered The Winds of Winter.”

He added: “Winter is still coming, and Winds remains my priority, as much as I’d love to write an episodes of House of the Dragon.”

Martin also shared his disappointment at the cancellation of Jane Goldman’s separate spin-off series, which has been dropped by HBO after a pilot episode was produced.

He said he was “saddened” at the cancellation of the series, which starred Naomi Watts, and added that he believes it had nothing to do with House of the Dragon.

“Heartbreaking as it is to work for years on a pilot, to pour your blood and sweat and tears into it, and have it come to nought, it’s not at all uncommon,” Martin wrote.

He added: “I’ve been there myself, more than once. I know Jane and her team are feeling the disappointment just now, and they have all my sympathy.”

Read more: Martin says fan response to Thrones finale was “toxic”

House of the Dragon is based on Martin’s Fire & Blood, which recounts the history of the Targaryen dynasty.

Ryan Condal, co-creator of the sci-fi series Colony, will serve as showrunner, alongside seasoned Thrones director Miguel Sapochnik, who helmed Battle of the Bastards and The Long Night.