Ariana Grande has admitted that she had reservations about the release of her runaway hit single ‘Problem’.

‘Problem’ proved to be an instant success after being downloaded 438,000 times during its first week on sale and is the fourth-best-selling debut ever for a female artist.

Speaking about her initial thoughts on the Max Martin-produced track compared to her previous material she said: “It was so different from me.”

After some encouragement from 'Right There' collaborator Big Sean, the 20-year-old singer and actress decided to take a risk.

The pony-tailed pop star explained to Entertainment Weekly: “He was like, ‘You’ve got a beautiful voice, but this is pop music – you gotta take a risk. You gotta let go and have fun.’ So I did.”

She added: “It didn’t make sense to me as a single until I heard it completely mixed, and then I was like, ‘Ohhhhh, s***!’”

Whilst ‘Problem’ – featuring Iggy Azalea – continues to light up the charts, fans are still waiting to see the video which Ariana has promised will premiere very soon.

Watch Ariana Grande performing ‘Problem’ live below: