The writer has been a regular in the HBO show's Comic-Con panel while his publisher Random House typically has a party at the event but Martin has excused himself this time, reported Entertainment Weekly.
The season 5 of 'Game of Thrones' premieres April 12.
"I have too much to do. Too many things on my plate. Son of Kong foremost amongst them," Martin wrote on his blog. "Son of Kong" is the pet term the author uses to describe "The Winds of Winter".
"Should I complete and deliver Winds of Winter before these cons roll round, I reserve the right to change my mind," he joked.
It looks like the author is nearing the end of his sixth "A Song of Ice and Fire" novel as the first of these fan events is only four months away.
His last book, 2011's "A Dance with Dragons", was originally supposed to end deeper into his saga.
The final planned book is titled "A Dream of Spring".
