U2 are recording a "futuristic" new album, according to their producer RedOne.

In an interview with Billboard, RedOne, who has previously worked with Lady Gaga, confirmed that he had been collaborating with the Irish band.

"We've put down a few ideas, but we don't know how many will end up on there," he said.

"They have a very special way of working. A song is never done until the day before it comes out almost, so you never know."

He added: "They're always experimenting, so it's not like, 'OK, we're finished.' It's still an ongoing process. Bono described [the album as] 'futuristic'. U2 going sci-fi, or something [laughs].

"That's how he described it, but I don't know."

U2's last album 'No Line On The Horizon' was released in 2009. The band are due to headline the Glastonbury Festival in June.

(by Jason Gregory)