The 34-year-old actor will portray lieutenant colonel Eric Savin, who is in charge of Project: Ultra, reported Ace Showbiz.
The character made his debut in Marvel comics in the late '80s and was brought back to life as cyborg mercenary Coldblood after stepping on a land mine.
"Iron Man 3" will be loosely based on Warren Ellis' six-issue "Extremis" comic book series, which follows a new origin story that focuses on nanotechnology.
Robert Downey Jr reprises his role as Tony Stark aka the armored hero, with Gwyneth Paltrow and Don Cheadle returning as Pepper Potts and Rhodey respectively.
In addition to Kingsley, Pearce and Dale, another potential new cast is Rebecca Hall.
"The Town" star reportedly is in talks to play a sexy scientist which was initially offered to Jessica Chastain. The female character plays a pivotal role in the creation of nanotechnology that winds up being sold to terrorists.
The Shane Black directed film will go on floors this month.
