Green Day have postponed the beginning of their 2013 arena tour while Billie Joe Armstrong continues rehab.

The band's frontman went into treatment for substance abuse problems in September when he smashed a guitar and swore multiple times on stage in Las Vegas, and the group have now called off the remainder of their 2012 club dates and pushed back the beginning of next year's tour.

"Obviously, the timing for this isn't ideal, but Billie Joe's well-being is our main concern. We are happy to say that Billie Joe is doing well, and we want to thank you all for the outpouring of support and well wishes that we have received, and we can't wait to see you all again soon," Bassist Mike Dirnt said in a statement released on Monday.

Mike previously revealed Billie Joe's stint in rehab was "killing" the band. "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," he explained.

The Grammy Award winners have also moved up the release date of their latest album Tre, which will now be released on December 11 rather than next year as originally planned.