Green Day's Mike Dirnt says Billie Joe Armstrong's ongoing stint in rehab is ''killing everyone''.

The group's frontman went into treatment for substance abuse problems in September after he smashed a guitar and swore multiple times on stage in Las Vegas, and bassist Mike says the band are all behind him and just want him to get healthy.

He told Kerrang magazine: ''Billie doesn't take things lightly and he wouldn't take rehab lightly, either. He's in the middle of some really big things, but we're going to pull through. It's killing everyone. Green Day have never been a band that sits still, but sometimes you have to step back and let life go on rather than try to control everything.''

Mike admitted it was difficult postponing upcoming shows, but says Billie's health was the most important issue.

He said: ''I know that my friend's life is in danger and that's all I care about. We're brothers-in-arms waiting for Billie to return healthy, but we're not going to force anything. Tre [Cool] and I will be standing here for Billie.''

Earlier this week, the chairman of Warner Bros records, Rob Cavallo, said he did not know whether the rocker will leave rehab before Christmas.