MTV will pay tribute to the 'Baby One More Time' singer at tonight's event, at which Spears is nominated for two awards.
"Who isn't a Britney Spears fan?" Lovato told MTV News. "My favourite Britney Spears song is 'I Wanna Go', 'cause it's the latest song that she has and I love it.
"Cause she's the ultimate pop star," Lovato added, when asked why Spears deserved the tribute. "Nobody can touch her.
"She's been around for such a long time now and she's the epitome of pop. So when I think of pop music I think of her."
Lovato will release her third studio album Unbroken on September 20.
Watch Britney Spears's recent promo for the MTV Video Music Awards 2011 below: