<Li> Gwyneth Paltrow as Pepper Potts: Stark's closest friend, budding love interest, and business partner; Pepper is promoted to CEO of Stark Industries . On her character's promotion, Paltrow opined "When we start Iron Man 2 Pepper and Tony are very much in the same vibe...as the movie progresses, Pepper is given more responsibility and she's promoted and it's nice to see her sort of grow up in that way . I think it really suits her, the job fits her really well ." Paltrow expressed excitement about working with Johansson . </Li> <Li> Don Cheadle as James "Rhodey" Rhodes: An officer in the U.S. Air Force and Tony Stark's close personal friend who later operates the War Machine armor . Cheadle replaces Terrence Howard from the first film . Cheadle only had a few hours to accept the role and did not even know what storyline Rhodes would undergo . He commented that he is a comic book fan, but had not previously participated in comics - themed films due to the scarcity of black superheroes . Cheadle said he thought Iron Man was a robot before the first film came out . On how he approached his character, Cheadle stated "I go, what's the common denominator here? And the common denominator was really his friendship with Tony, and that's what we really tried to track in this one . How is their friendship impacted once Tony comes out and owns' I am Iron Man'?". Cheadle said his suit was 50 pounds (23 kg) of metal, and that he could not touch his face while wearing it . </Li> <Li> Scarlett Johansson as Natalie Rushman / Natasha Romanoff: An undercover spy for S.H.I.E.L.D. posing as Stark's new assistant . Johansson dyed her hair red before she landed the part, hoping that it would help convince Favreau that she was right for the role . On why she chose the role, Johansson said, "the Black Widow character resonated with me...(She) is a superhero, but she's also human . She's small, but she's strong...She is dark and has faced death so many times that she has a deep perspective on the value of life...It's hard not to admire her ." She stated that she had "a bit of a freak - out moment" when she first saw the cat - suit . When asked about fighting in the costume, Johansson responded "a big part of me is like' can I move in this? Can I run in it? Can I like throw myself over things with this?' And I think just the prep, you just have to put in the hours . That's what I realized is that just putting in the hours and doing the training and repetition and basically just befriending the stunt team and spending all day, every day, just over and over and over and over until you sell it ." </Li> <Li> Sam Rockwell as Justin Hammer: A rival weapons manufacturer . Sam Rockwell was considered for the role of Tony Stark in the first film, and he accepted the role of Hammer without reading the script . He had never heard of the character before he was contacted about the part, and was unaware Hammer is an old Englishman in the comics . Rockwell said, "I worked with Jon Favreau on this film called Made . And Justin Theroux, who wrote the script, is an old friend of mine, they sort of cooked up this idea and pitched it to Kevin Feige . What they did, they were maybe going to do one villain like they did with Jeff Bridges, but then they decided to split the villains . And really Mickey (Rourke) is the main (villain), but I come to his aid ." Rockwell described his character as "plucky comic relief, but he's got a little bit of an edge". </Li>

Who plays agent romanoff in iron man 2