In January, it was alleged that Ronan had signed on for The Hobbit as part of the producer's attempts to introduce more female characters.
However, the Academy Award-nominated actress claimed that she has yet to officially join the Lord Of The Rings prequel.
"No, I'm not actually attached. I'm not confirmed," Ronan told CinemaBlend. "But they are introducing new characters. I know that, a few new characters."
The actress also responded to speculation she might play an elf in Jackson's two-part epic, admitting that it sounded like a distinct possibility.
"I think I could pass for an elf. I think if I had the right ears," she joked. "I wouldn't want to be a hobbit. Certainly not."
If Ronan does join The Hobbit, it would mark the second time that she has worked with Peter Jackson, following his 2009 adaptation of Alice Sebold's The Lovely Bones.
It was recently suggested that Ronan was in line to play Snow White in Tarsem Singh's new adaptation of the classic fairytale, until Lily Collins was announced to have been officially cast in the role yesterday.
The first instalment of The Hobbit is expected to be released sometime in 2012.
Watch our recent interview with Saoirse Ronan below: