Details of new films including the title of the third instalment of Avatar, an addition to the Star Wars franchise and a sequel to Freaky Friday have been announced at a giant Disney fan event.

Filmmaker James Cameron told a 12,000-strong audience that Avatar: Fire And Ash will "not be what you expect" while US actor Jon Favreau teased a new Star Wars film titled The Mandalorian And Grogu, starring Pedro Pascal.

Actors Lindsay Lohan and Jamie Lee Curtis, stars of the 2003 comedy Freaky Friday, also appeared on stage to promote Freakier Friday, which is set for 2025.

The announcements were made at D23, the biennial convention for members of the official Disney fan club, in California on Friday.

Avatar director Cameron made a surprise appearance alongside the film's stars Zoe Saldana and Sam Worthington.

The science fiction epic, set for release on 19 December 2025, comes after 2009's Avatar and its sequel Avatar: The Way Of Water, which was released in 2022.

"The new film is not what you expect, but definitely what you want," Cameron told the audience.

He said it was "too soon" to share footage but let the audience look at "cool concept art" which featured the characters in the sky and surrounded by fire.

"There are new cultures and settings and creatures, and new biomes," he said.

"You will see a lot more of Pandora, the planet, that you've never seen before."

Lohan and Curtis were greeted with a standing ovation at the eighth D23 event, which is being held from 9 to 11 August at the Anaheim Convention Centre in California.

Curtis described Freakier Friday - about a mother and daughter who switch bodies thanks to a magical Chinese fortune cookie - as "more fun and more emotional" than their 2003 film.

"We've stayed in touch throughout the years and we're very close to each other so it feels like we are picking up from where we left off, which is really beautiful," Lohan said.

Oscar-winner Curtis told the audience: "We love these characters, we love each other, we love you and you love us and the movie and the story and what it means to you - that's why we're here."

The pair confirmed One Tree Hill's Chad Michael Murray and NCIS actor Mark Harmon are reprising their roles in the sequel.

The audience was shown a trio of pictures from the new film including an image of Curtis sporting a silver bobbed hairdo while driving Lohan in an open top car.

In the new film, Lohan's character Anna Coleman has a daughter of her own.

Freaky Friday, based on a 1972 novel by Mary Rodgers, was also made into a movie in 1976, starring Jodie Foster and Barbara Harris.

As for the new Star Wars film, The Mandalorian, executive producer Dave Filoni said production started "a few weeks ago" and it is due for release in May 2026.

"We are putting Star Wars back on the big screen," Mr Filoni said.

The announcement came after Pixar's chief creative officer Pete Docter announced The Incredibles 3 was also in the works.

He confirmed Brad Bird, the writer and director behind the first two films, has returned for the next adventure from the beloved undercover super-family.

Frozen director Jennifer Lee also appeared to confirm there will be two more films added to the Frozen franchise.

"Coming out of Frozen 2, we still have some questions... Now you see why it will take two films to answer them," she teased.

Lee shared a first look at concept art for Frozen 3, which is slated for 2027.

Later at the event, Toy Story star Tom Hanks joined a group of the original film's creators including Pete Docter, now chief creative officer at the animation studio behind it, Pixar, on a panel.

Since the film's initial release in November 1995, Toy Story has become a celebrated franchise with three sequels and a fourth due in 2026.

Hanks voices pull-string cowboy toy character Woody.

And during the panel, the audience was shown a printed list titled "ideas for Woody's pull-string dialogue lines" dated 3 February 1993.

There were three handwritten phrases at the bottom, including Hanks's famous line "there's a snake in my boot".