Pop star Katy Perry plans to open up about her feud with singer Taylor Swift because she refuses to allow anyone to "defame" her character.

The `Dark Horse` hitmaker, who is reportedly planning to take aim at her 24-year-old rival at the Super Bowl Sunday with her new song `She's So Creepy`, admits she won't hold back when it comes to defending herself, reports femalefirst.co.uk.

Asked about the tension between her and the `Blank Space` singer, she told Billboard.com: "If somebody is trying to defame my character, you're going to hear about it."

The duo reportedly fell out last year when Taylor revealed one of her latest tracks `Bad Blood` was written about another famous singer, calling her a "straight-up enemy."

While Swift didn't name Perry, the `Roar` hitmaker fuelled rumours the comments were about her when she tweeted the next day: "Watch out for the Regina George in sheep's clothing," referencing a character from the film `Mean Girls`.