LOS ANGELES (AFP) - Warner Bros released the official full-length trailer for long-anticipated sci-fi sequel Blade Runner 2049 on Monday at an event in Los Angeles with stars Ryan Gosling and Harrison Ford.

Denis Villeneuve's follow-up, set some 30 years after the events of cult classic Blade Runner (1982), sees Ford reprise his role from Ridley Scott's original as Rick Deckard, a Los Angeles cop who hunts rogue androids.

"The character is woven into the story in a way that intrigued me. There's a very strong emotional context... I think it's interesting to develop a character after a period of time, to revisit a character," said Ford, 74, at a discussion panel at the Imax headquarters.

Gosling, 36, leads a cast of newcomers, including Robin Wright and Jared Leto.

The footage was praised by movie websites, which noted Villeneuve's success in emulating the gritty, dust-covered cinematography of the original.

But it reveals nothing of the plot beyond the studio publicity, which says a new "blade runner", LAPD Officer K (Gosling), unearths a long-buried secret that has the potential to plunge what is left of society into chaos.

K's discovery leads him on a quest to find Deckard who has been missing for 30 years.

The trailer follows an early teaser in December and more extensive footage shown at CinemaCon, the Las Vegas convention for theatre operators, in March.

"Prepare to start going steady with edge of your seats," Gosling joked as he introduced bleak scenes from Los Angeles and a snow-bound Las Vegas, all of which were filmed in Budapest.