Victoria Beckham impresses sons with Bieber video

Victoria Beckham's sons are "so impressed" that she is starring in a video alongside Justin Bieber.

The singer-turned-designer is appearing alongside the pop sensation in a star-studded advert for Fashion's Night Out, a global shopping event.

Usher, Taylor Swift and Glee actor Darren Criss also feature in the black and white clip to promote the event, but the Beckham boys are big fans of Justin and were most excited about Victoria working with the Canadian star.

"VB and JB!! @justinbieber Romeo and Cruz so impressed!! join us @VogueMagazine #FNO x vb [sic]," she wrote on her Twitter profile.

Set to Darren Criss' rendition of Madonna hit Dress You Up, designers Marc Jacobs and model Karlie Kloss also appear to announce that the event will take place on September 6 in cities all over the world including London, New York, Paris, Milan, Sidney and Berlin.

"So check this out - Fashion's Night Out is back," Usher says as the clip opens.

The footage cuts to glamorous Victoria, who is sporting a casual cool black suit and a special FNO T-shirt designed to raise money for the New York City AIDS fund.

"Fashion's Night Out…" she leans into the camera with a conspiratorial smile. "Hit the streets and shop."

"I'll definitely be there," Justin Bieber adds. "Who doesn't want to meet models, right? You bring your friends, I'll bring my friends, we can all hang out. Will you be there?"