The famously feuding trio have been busy holed up in "a little cottage in the boonies on a little river" in Florida, Billboard.com reported Monday. The album will produced by Steve Albini and Jack White and released on the Virgin label next year.
"All the same passions and problems are there," Pop told Billboard. "But the problems are in a more muted style. I'm still the showoff in the group that gets all the attention. Everyone has their role.
"It's pretty much the way it was in high school."
Pop said he set his mind on making the reunion work back while recording his 2003 solo album, "Skull Ring," with a variety of guest musicians.
"Suddenly they (the Ashetons) were in sight and in mind," he said. "I thought, 'If I'm going to try a couple tracks with Green Day, why not get the original band?'"