The Parks and Recreation actress told Access Hollywood that her role in the comeback film required her to treat Jim Henson's puppets badly, a concept which she found "tough".
Jones explained: "I play an executive at a TV network who gives them a shot, and I'm kind of a little bit mean to the Muppets, which was hard for me! [It was] very hard for me. It was tough."
However, she insisted that her character isn't all bad, adding: "I'm just stressed out - like most executives."
The Muppets star Jason Segel recently admitted that it was a "struggle" to get Hollywood to back the film.
Segel, who also produced the project, has described it as a dream come true and said that he enjoyed making the film.
The Muppets will debut in US cinemas on November 23 before arriving in the UK on February 17, 2012.
> 'The Muppets': New international poster released
Watch the trailer for The Muppets below: