Bassist Ted Dwane previously described the band's second studio album as "Black Sabbath meets Nick Drake". However, singer Marcus Mumford has now denied claims they are writing "doom-folk".
Mumford told NME: "That was a joke to an American journalist who didn't understand the concept of sarcasm. I called Ted [Dwane, double bassist] and was like, 'Ted, what have you done? We spent our whole first album trying to avoid being pigeonholed!'"
Mumford added that the follow-up to 2009's Sigh No More will serve as an "evolution, not revolution" of their work.
The frontman also revealed that he can't promise the album will be recorded in time for release this year. He explained: "We don't want to put that added pressure on ourselves.
"Everyone's just letting us get on with it. The only people that have heard it are Dravs, our manager, and us. No-one else has been involved in the process - so it means that we might have completely f**ked it up!"
Mumford & Sons recently performed for Barack Obama and David Cameron at the White House during a state dinner.
Watch the music video for Mumford & Sons' 'Little Lion Man' below: