In the upcoming film, the actress plays the driven Violet, who lives in San Francisco with her fiancé (Jason Segel). The couple must relocate to Ann Arbor when Violet gets the opportunity to work in the psychology department at the University of Michigan.
Blunt, who previously suggested she would be open to superhero or sci-fi film roles, told USA Today: "I'm quietly ambitious. Is there such a thing?
"I love this job. I'm in love with this job. I never thought I'd be in love with it because I never had the intention to be an actress. So if I love a part, or want a movie, I'll definitely make a play for it."
Blunt's career has ranged from playing a snobbish fashion assistant in The Devil Wears Prada to portraying Queen Victoria in The Young Victoria.
"But I don't think I'd sacrifice a relationship or something more than this business for it," Blunt added. "Violet's main problem is that she has to define herself by that job. She credits a lot of her happiness to that job. I think a lot of people do that.
"There's a lot more to how I like to define myself than just by my job."
The Five-Year Engagement arrives to theatres on April 27 in the US and June 22 in the UK.
Watch the trailer of The Five-Year Engagement below: