Justin Bieber wins 3 AMAs, including artist of the year

Justin Bieber accepts the award for favourite male artist - pop/rock at the 40th Annual American Music Awards in Los Angeles, on Sunday Nov. 18, 2012. (Invision - AP / John Shearer)

America proved its Bieber Fever was strong: The teen singer dominated the American Music Awards on Sunday night.

Bieber's wins included the show's top award, artist of the year.

The singer's mom joined him onstage as he collected the top award.

He looked to his mom: "I wanted to thank you for always believing in me."

He said it's "hard growing up with everyone watching me" and asked that people continue to believe in him.

The 18-year-old also won favourite pop/rock album for "Believe" and male artist.

He performed two songs at the award show, one stripped and another upbeat with Nicki Minaj. As Bieber won his second award, he was kissed on the neck by Jenny McCarthy, who presented the award.