NEW YORK — Game of Thrones returns for its season seven premiere on July 16, HBO announced Thursday in an elaborate marketing stunt which elated and bemused fans of the hit fantasy show.

In a gimmick described by the New York Times as "memorably misguided," the US cable network revealed all in a Facebook Live video showing a block of ice which viewers had to melt by commenting "Fire" to reveal the date.

The process was supposed to take a touch under 15 minutes — already a long time to be concentrating on a block of slowly melting ice — but the video malfunctioned several times, drawing out the process to more than an hour.

The debacle sparked snarky posts on Twitter, where #GoTS7 remained one of the top trending hashtags worldwide for hours after the announcement.

"Whoever is in charge of the @GameofThrones S7 premiere date reveal is getting a visit from Septa Unella," tweeted one frustrated fan, invoking the brutal nun of the show’s fifth and sixth seasons.

"Next year, @HBO, a press release will do," said fan account @BeautyBrienne.

Game of Thrones tells the story of noble families vying for control of the Iron Throne, all the while keeping one eye on the "White Walkers" leading hordes of the undead toward an invasion from the North.

Since its debut in 2010, the fantasy epic — which has 38 Emmys, more than any other narrative show in history — has been the target of criticism for senseless violence and, more controversially, its pervasive use of rape as a dramatic device.

The adult themes have not deterred viewers of the show, which has grown its audience in the US to more than 25 million, and is breaking records across the world.

Season six of Game of Thrones was the first to move beyond George R R Martin’s A Song of Ice and Fire novels.

Showrunners David Benioff and D B Weiss last year announced a shortened run of episodes for the final two seasons after HBO had already confirmed season seven would return in summer, a departure from the usual April premieres.

The show has been teasing winter’s arrival since its pilot episode, and with the season six finale entitled The Winds of Winter, the camera crew has been forced to wait for colder weather.

Benioff told fans at San Diego Comic-Con in July last year shooting would not finish until February and that "there’s no way to get the show out there until summer." — AFP