Avatar: The Way of Water London Premiere

One of the most delayed sequels in blockbuster history finally hit the big screen on Tuesday as "Avatar: The Way of Water" got its much-anticipated world premiere in London.

The 13-year wait for a follow-up to "Avatar", the biggest-grossing film of all time, cannot come too soon for cinemas around the world still struggling from the impact of the Covid pandemic.

The public will get to see James Cameron's three-hour opus next week, with the director hoping it will justify his dream of establishing a franchise on a par with "Star Wars" and the "Marvel" juggernaut.

The legendary filmmaker admitted to having some nerves ahead of the premiere.

"I've always been nervous every time before we put a movie out into the marketplace and this is a particularly fraught time because, after the pandemic, the market has contracted somewhat," he told the BBC from the red carpet.

But Cameron added he was confident that the sequel to his 2009 blockbuster delivers.

"The film is a good ride. It's a good experience. It's powerful. It's emotional. People are crying, they're weeping their eyes out coming out of the theatre in a good way."

Having been re-released around the world in recent months, the first "Avatar" is now just shy of $3 billion in worldwide revenue.

But Cameron's initial hopes of having a sequel out by 2014 saw repeated delays as his technical ambitions grew.

- 'Big fan' -

The second film continues the mix of sci-fi and eco-politics -- returning to the planet Pandora where the Na'vi characters struggle to fend off rapacious humans -- as well as the groundbreaking use of 3D and cutting-edge cinematic wizardry that made the original such a box office hit.

Stars Sam Worthington, Zoe Saldana and Sigourney Weaver return, alongside new additions including Kate Winslet, a quarter-century after her world-beating collaboration with Cameron for "Titanic".

Some fans arrived in central London early to land a precious wristband providing access to the red carpet at the evening screening.

Dobrinka Perry had even painted her face blue in honour of the budding franchise's Na'vi characters.

"I'm a big fan," she told AFP, drawing comparisons with plotlines and her own life, such as environmental campaigning.

"I am also a fighter, I fight for the tree of my family, for my Pandora... and especially for what we are going to leave to our kids later."

Nelly Szabo, 23, had also turned out for the premiere with high hopes.

"We've been waiting a long time for it," she said of the sequel. She added that the first one "was amazing so our expectations are very high."

The follow-up remains a huge bet for Cameron and for Disney, who have ploughed hundreds of millions of dollars not only into this film, but a third instalment that has already been shot.

That is not the end: Cameron has planned the series through to a fifth entry, with new films due every two years until 2028.

Cameron said he was "reasonably confident" they would be released.

"We did well with the first film and that allows us to go on... we got to see what happens."