(CNN) -- Metallica says it is postponing its tour in Australia and New Zealand after lead vocalist James Hetfield reentered rehab.
The heavy metal band made the announcement Friday in a series of tweets.
"As most of you probably know, our brother James has been struggling with addiction on and off for many years," the band's tweet said. "He has now, unfortunately, had to re-enter a treatment program to work on his recovery again."
The band members said they planned to make their way to Australia and New Zealand "as soon as health and schedule permit."
"Once again, we are devastated that we have inconvenienced so many of you, especially our most loyal fans who travel great distances to experience our shows," the band's tweet read. "We appreciate your understanding and support for James & thank you for being a part of our Metallica family."
All tickets, "including Enhanced Experiences and Black Tickets," will be fully refunded, the band's tweet read.
Hetfield's struggle with addiction was seen in the 2004 documentary "Some Kind of Monster" that chronicled the recording of the band's album "St. Anger."