HBO executives have said they are "not concerned" about continuing Game of Thrones if George RR Martin does not finish his next novels in time.
The forthcoming fifth season will draw heavily from Martin's fourth and fifth novels A Feast of Crows and A Dance with Dragons in the A Song of Ice and Fire series.
However, should Martin's next novels The Winds of Winter and A Dream of Spring not come out before the following sixth and seventh season, producers have said they intend to finish the TV show's run come what may.
Asked if there would be anything "short of a nuclear war" that would prevent Game of Thrones from completing its entire story as planned, HBO programming president Michael Lombardo said: "No ... we're committed to it and [showrunners David Benioff and Dan Weiss] are committed to it."
Lombardo added that Martin had played a key role in developing the last series, but said HBO was not concerned about continuing the series should Martin not finish writing his books in time.