She’s made so secret about her support for Obama over the years and has performed to support him during his campaign trail on a number of occasions.

And on Saturday Katy Perry fulfilled her patriotic duty once again as she headlined the Kids’ Inaugural Concert in Washington.

Dressed in a star spangled banner themed 50’s Pin-up style costume, the singer rocked the stage in front of the famous First Family in honour of the children of military families nationwide.

The singer took to the stage in what looked like a white bodice with a blue starred skirt, before she stripped it off to reveal a pair of red and white striped hot pants below.

While her hair was styled in neat curls, she wore a bandana around her neck.

Hot pants: Katy started her performance in a skirt before revealing her red and white hot pants on beneath

The singer even accessorised her Uncle Sam style outfit with a matching microphone featuring stars and stripes.

As Katy, who is dating John Mayer, set the stage alight with her bright and bubbly pop music, America’s Got Talent host Nick Cannon oversaw the evening.

The brunette beauty performed Teenage Dream, Part of Me, Wide Awake and Firework, which she sang in front of a photo montage of the President with children.