Green Day's new material has been described as 'amazing' by the band's long-time producer and collaborator, Rob Cavallo.
The pop-punk icons, who were recently inducted into the Rock And Roll Hall Of Fame, are rumoured to be releasing an album later this year - their first since the band's Uno! Dos! Tre! trilogy in 2013.
Now Rob Cavallo, who has produced all of the band's albums since Dookie and is also chairman of Warner Bros Records, has revealed how their new material is shaping up - saying that frontman Billie Joe Armstrong is 'on top of his game'.
"I recently heard five new songs that Billie has written and demoed," he told Kerrang magazine. "Let me tell you, they were just fantastic. He is absolutely at the top of his game. Fans can be sure that when they do return, the music will be amazing."
Last year, Armstrong excited fans when he hinted for the first time that the band will return in 2015. He decided to post on Instragram shortly before embarking on a DIY project. "I'm in a hardware store in queens. and this is on my mind. #greenday15 #thefutureisnow #greendayforever"
Their last UK gig was the colossal 99 Revolutions Tour in 2013 that included a stellar show at London's Emirates stadium - where the band broke the attendance record.
This week also saw a very early video of Green Day performing on their high school campus emerge online.