Scarlett Johansson has promised “lots of surprises” from her upcoming superhero film Black Widow.

The US actress has played the character in the Marvel Cinematic Universe (MCU) since 2010, but this will be the first time she has had a standalone movie.

Johansson introduced Black Widow, also starring Rachel Weisz and David Harbour, on stage at Marvel Studios’ Comic-Con panel, as the company revealed phase four of the MCU.

Speaking after the announcement, Johansson said she is “so excited” to reprise the role.

She told PA: “We’re going to learn about what haunts this character. You learn a lot about her, there’s a lot of surprises.

“It’s pretty raw. We go to the brutal, uncomfortable places.”

Johansson, 34, first played Black Widow, a former Russian spy who defected to the Avengers, in 2010’s Iron Man 2.

2019 Comic-Con – Marvel Studios
Rachel Weisz, left, and Scarlett Johansson, who will star in Black Widow (Chris Pizzello/Invision/AP)

“I feel like I’ve in a lot of ways grown up with this character”, she said.

“To be able to come back every two years to this character and peel away layer after layer over this period of time and with this unbelievable fan base, it’s kind of incredible.”

British actress Weisz, 49, said the offer to work on the film came “completely out of the blue” from director Cate Shortland.

Oscar-winner Weisz revealed she was so keen to work with the Australian filmmaker that she said “yes” to the part before seeing the script.

2019 Comic-Con – Marvel Studios
David Harbour, from left, O T Fagbenle, Rachel Weisz and Scarlett Johansson will all star in Marvel superhero movie Black Widow (Chris Pizzello/Invision/AP)

She said: “She’s someone I’ve wanted to work with for a long time so when I heard it was her, I was kind of blown away. Actually, she works very rarely, she’s a real auteur.

“It was incredible, and I hadn’t seen the script yet, so that was a very big draw. And Marvel are our contemporary mythology, they’re the great storytellers.”

Black Widow is set to arrive in cinemas on May 1 2020.