"Thank you @arianagrande for having me at your very special One Love benefit concert in Manchester!" Cyrus wrote alongside a video from the pair's duet of 'Don't Dream It's Over" for Happy Hippie's Backyard sessions in 2015. "Always been a great friend to ME & @happyhippiefdn !!!!"
Justin Bieber, Katy Perry, Niall Horan, the Black Eyed Peas, Coldplay, Usher and Pharrell Williams are also set to perform at the One Love Manchester benefit concert at Emirates Old Trafford cricket ground on June 4, which sold out in minutes on Thursday.
Proceeds from the event will go to the Red Cross’ Manchester Emergency Fund, aiding those affected by the bombing at Grande's Manchester Arena concert on May 22, in which 22 were killed and 59 were injured.