Ariana Grande has defended Justin Bieber after he sang with a backing track during his surprise appearance at Coachella festival last weekend.

The 25-year-old singer, who brought 'The Biebs' on stage for her recent set at Coachella Valley Music and Arts Festival, has hit back at comments criticising the performance, saying "people don't know how it feels to be under scrutiny."

Responding to a tweet The Sorry hitmaker posted on social media, Grande posted: ''we also decided to do this ten minutes before my set started. we had 0 soundcheck, 0 rehearsal. u were singing with the back tracking like most cameos do. people are bored. people don't know how it feels to be under such scrutiny. the world was happy to have u on stage again. 

"your fans, friends & the world is thrilled to have you back. everyone was so happy to see u smile like that. no one will ever understand how it feels to be u, but it’s not their job to. take care. make music. u are loved."

Bieber and Grande performing at Coachella

Bieber also took to Twitter to defend himself after he came under fire from E! host and former reality star Morgan Stewart for lip-syncing. 

Writing to Stewart on Twitter, he said: "just saw a video of you ripping me to shreds saying I was lip-syncing. They played the song and i just sang overtop of it.. regardless why spend your time tearing people down," he said. 

He continued, "@Morgan_Stewart imagine if you spent even half the time you spend laughing at other peoples expense actually building people up and encouraging people how much positivity you could bring. What hurts about this is the fact that you have a platform to make a difference".

Bieber recently opened up about his Irish roots on Instagram claiming that he was 60 percent Irish.

For more music news and reviews, click here