The front man singer for the rock band "Green Day" is entering rehab after having an on-stage meltdown at the iHeartRadio Music Festival in Las Vegas.

Billy Joe Armstrong is reportedly set to undergo treatment for substance abuse. A spokesperson for the rock group has confirmed the news and the band have also postponed several upcoming promotional appearances.

''Green Day' wants to apologize to those they offended at the 'iHeartRadio Festival' in Las Vegas. The band regretfully must postpone some of their upcoming promotional appearances," the spokesperson of the Grammy-winning band told TMZ.

The famous group's front mad had a very public meltdown on-stage over the weekend where Green Day was performing at the star-studded event. The 40-year-old Armstrong was videotaped ranting and screaming profanities and he also slammed Justin Bieber during the band's performance at the annual three-day festival before violently smashing his guitar on-stage. Armstrong was complaining that their performance of their hit song "Basket Case" had been cut short so that singer Usher could have more time when the teleprompter showed that the band only had one minute left.

"One minute left. One minute f**king left. You're going to give me one f**king minute? Look at that f**king sign right there - one minute," Armstrong shouted at the Las Vegas crowd. Both Armstrong and bass player Mike Dirnt was also seen on the video smashing their guitars before walking off the stage.

Meanwhile, Billy Joe Armstrong has already been hospitalized in Italy earlier this month due to an undisclosed ailment but he recovered just in time for his band to perform at the "MTV Video Music Awards." Green Day will release their new album "Uno" which is the first in a trilogy of records and the rock band is due to kick off a new United States tour in Seattle on November 26.

Check out the footage of Green Day's performance at the iHeartRadio Music Festival in Las Vegas.

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