Green Day are prioritising Billie Joe Armstrong's recovery from substance abuse.

The rockers have apologised for cancelling ''everything'' - including concerts - over the next few weeks because they ''have to put the life of our friend in front of everything else'' while the frontman recovers in rehab for substance abuse.

Bassist Mike Dirnt blamed the recording of their three albums 'iUno!', 'iDos!' and 'iTre!' for Billie's breakdown, saying: ''Hindsight is 20/20... it was a tremendous undertaking. It catches up with you a little bit.

''We definitely jumped off a moving train. All that inertia. There were signs of things hitting the fan, we hadn't slept in forever.''

40-year-old Billie shocked fans with his onstage meltdown at the iHeartRadio Music Festival in Las Vegas in September.

He screamed profanities after being informed the band's set would be cut short, before smashing his guitar and storming off stage.

Mike is confident Billie will recover, and although he hasn't seen his bandmate ''in weeks'' he insists the band will be back together soon.

Speaking on the UK's BBC Radio 1, he said: ''We're still getting ready for the next phase.''

'iUno!' was released on September 24, while '¡Dos!' will be released on November 12 and '¡Tré!' follows on January 14 next year.