Natalie Portman, John Krasinski go on nostalgic adventure with 'Fountain of Youth'

Director Guy Ritchie's new action-adventure Fountain of Youth did not lead its stars Natalie Portman and John Krasinski to the source of immortality, but it did take them back to the movies they grew up watching.

The Hollywood stars play estranged siblings Charlotte and Luke, who put their differences aside to embark on a globe-trotting quest to locate the mythical spring that, according to legend, grants eternal youth to anyone drinking from it or bathing in it.

Making the movie was a "big nostalgia hit", said Krasinski.

"This is one of those big adventure movies that made you want to be in the movies," the 45-year-old actor and filmmaker said. "This is what I used to pretend to do. So to be in a movie that I used to pretend to be in with my brothers is totally surreal."

Domhnall Gleeson, Eiza González, John Krasinski, Benjamin Chivers, Natalie Portman, Carmen Ejogo, Laz Alonso and Arian Moayed attend Apple's "Fountain of Youth" premiere at American Museum of Natural History on May 19, in New York.

The film draws inspiration from family favourites such as the Indiana Jones and National Treasure franchises, Portman said.

"This one has an amazing sibling rivalry at the centre, which is kind of a marked difference from Indiana Jones. But yes, of course all the adventure and the incredible locations and all of that imagination is definitely there," the 43-year-old Oscar winner said.

Ten years since their adventurer father's death, Luke is determined to continue honouring his treasure-hunting legacy, while art curator Charlotte has settled down in London.

Dealing with an acrimonious break-up with the father of her young son, Charlotte is lured into her brother's latest adventure, financed by a wealthy businessman played by Domhnall Gleeson.

Written by James Vanderbilt, Fountain of Youth opens with a high-energy chase sequence through the streets and landmarks of Bangkok and sees its characters journey to Irish waters, Vienna, Vatican City and the Pyramids of Giza.

The film reunites Ritchie with his The Ministry of Ungentlemanly Warfare and In the Grey star Eiza Gonzalez, who plays the mysterious Esme.

"This was a very different set because this is like a family-driven film. So there's children on set. And you are also the family of the travelling pants, you're travelling everywhere together," Gonzalez said.

"Half of that crew I'd worked with three times in a row, so it was sort of like going to camp."

Fountain of Youth will stream on Apple TV+ from May 23.