Country-pop superstar Taylor Swift has starred in a new commercial for Diet Coke and it focuses on having the confidence to stand in front of big crowds.

The 'I Knew You Were Trouble' beauty only appears for a few seconds towards the end of the advertisement, but she can be seen wearing a stunning dress and her trademark red lipstick before agreeing to head out on stage. 

In spring 2013, Swift partnered with the soft drinks brandand shot a 'Music That Moves' campaign video, telling the press that she was really excited to be working with such an iconic company: "We've been in conversations about this partnership that's going to include so many fun things having to do with the tour, having to do with Diet Coke in general - behind the scenes for a commercial shoot."

"I really can't wait to begin all this and I think it's going to be an extraordinary ride. I just wanted to tell you guys first because you guys have been so amazing - thank you for everything and I'll talk to you soon."

Watch the new commercial below: