The band, founded in Berkeley, California in 1987, canceled nine dates between now and December, and postponed 21 shows scheduled during January and February next year, it said in a statement. All the shows are in the United States.

"Obviously the timing for this isn't ideal, but Billie Joe's well-being is our main concern," said the band's bassist and co-founder Mike Dirnt, without explicitly referring to the singer's drug problems. "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," he added. Armstrong has checked in for rehab after an expletive-laden meltdown at a festival show in Las Vegas last month, according to the Los Angeles Times newspaper, which said he is being treated for "substance abuse issues."

Earlier this year the band announced a trilogy of albums, "Uno," "Dos" and "Tre," going on sale in September, November and January, as follow-ups to their Grammy-winning 2009 hit album "21st Century Breakdown."

The second album is still due out in November, but the release of "Tre" has been brought forward to December. Tickets for shows this year will be refunded, while new dates will be announced for the January and February shows.

"We feel bad we have to delay our tour, so to make up for it we want to give our fans the music earlier than we had planned," said drummer Tré Cool, real name Frank Edwin Wright III.

"If we couldn't be there to play it for you live, the least we could do was give you the next best thing," he added.