Rihanna asked a producer to create a song for her in two days.

The pop star approached Calvin Harris to work on her new album.

The 28-year-old was unable to create the track due to the unrealistic deadline he was given.

"Rihanna has been recording the new album and she said to me, 'You have to do something for it,' and so I sat there and said, 'OK I need to do this,'" Calvin revealed to BBC Radio One. "I sat in the studio and thought, 'OK I've got two days to do this.' Two days to make one of the best records I'll probably ever make in my life."

Calvin previously collaborated with Rihanna on the hit song We Found Love. Despite having experience in dealing with the international mega star, Calvin froze under such strict deadlines.

"So obviously I didn't do anything..." Calvin admitted. "Off the record I did make a pretty decent tune, but you can't work under that kind of pressure. Anyway I can't just go into a studio and go right at it like that."

Calvin's new album 18 Months was released last week.

It features his collaboration with Rihanna along with tracks he has produced with stars such as Ellie Goulding and Dizzee Rascal over the past 18 months.

Meanwhile, Rihanna has recently announced that she will be heading on a brand new worldwide tour this month.

Her 777 tour will see the singer head to seven different countries across one week to promote her new album Unapologetic.