As the premiere of ‘Game of Thrones’ season six draws near, author George R.R. Martin has admitted that he is far from finished when it comes to ‘The Winds of Winter,' the sixth installment of his novel series, ‘A Song of Ice and Fire,’ on which the hit HBO series is based.

According to Martin, the highly anticipated book is "not done, nor is it likely to be finished tomorrow, or next week."

The award-winning novelist has now failed to catch the two deadlines given to him by the publisher; in particular, the ‘Winds of Winter’ had been due before 2015 came to a close- the last deadline that should have enabled the sixth book to be published prior to the premiere of ‘Game of Thrones’ season six in April this year.

As such, the sixth season of the HBO series will air on screen before the release of its source material.

As he wrote on his blog, the 67 year-old novelist stated to his fans: "I won't make excuses. There are no excuses. No one else is to blame. Not my editors and publishers, not HBO, not [screenwriters] David [Benioff] and Dan [Brett Weiss]. It's on me. I tried, and I am still trying."

Martin added that he was not contented of some of the choices he made, bringing about revisions; this also caused him a great deal of stress and slowed down the pace of his writing.

“As the suspicion grew that I would not make it after all, a gloom set in, and I found myself struggling even more,” he admitted. “The fewer the days, the greater the stress, and the slower the pace of my writing became."

Laren Morgan, features photo editor at Entertainment Weekly's online service, posted on Twitter and stated, “In the time that #GeorgeRRMartin has been working on the #WindsofWinter I've had a baby, three different jobs and bought a house."

After Martin completes ‘The Winds of Winter,’ he still has to finish the last instalment in the novel series- ‘A Dream of Spring.’

The fantasy series has received widely positive reviews and moved on to becoming one of HBO’s biggest hits all over the world.

Meanwhile, a new book relating to ‘Game of Thrones’ is set to be released, addressing the scientific possibilities that can be linked to Martin’s fictional world.

As announced by publishing company Little, Brown, stand-up comedienne Helen Keen’s new book will look into the questions raised in Westeros using a new perspective.

As stated by a press release shared in Entertainment Weekly, Keen’s new book is "a myth-busting, mind-blowing, jaw-dropping and fun-filled expedition through Westeros and beyond."

She also shared how she has been a longtime fan of Martin’s books as well as the HBO TV series, saying: “… Writing what I hope will be the ultimate companion for anyone who has ever longed to lovingly hatch their own dragons, or brutally murder someone with molten gold, is a dream come true.”

As for ‘Game of Thrones’ season six, it is set to premiere on HBO this April.