Justin Bieber has revealed the reason behind his emotional outburst at the MTV Video Music Awards (VMAs), when he shed tears on stage.

The 21-year-old pop star, who started crying after he performed his new single, What Do You Mean?, admitted he couldn’t resist welling up, “overwhelmed” by the support of his fans at the August 30 ceremony.

“It was so overwhelming,” he told Jimmy Fallon on The Tonight Show. “I missed some cues so I was a bit disappointed about that.”

“But just the support … I didn’t expect them to support me in the way they did,” he continued.

“Last time I was at an awards show, I was booed.”

The Canadian singer said he was desperate for fans to appreciate his new music and said he felt “judged” after being in the spotlight for recent controversies.

“I wanted to win so badly and I wanted to do what I love, I just put everything on the line,” he explained.

“What was so special about the emotional moment, it was authentic and real … I was just wanting it so bad.”

Justin, whose fourth album will be released on November 13, also admitted he was “ranting” at one point during the interview with the US talk show host.