Katy Perry has written a poem to her fans ahead of her first Prismatic tour show.

The singer is due to open the world tour in Belfast tonight (May 7) before heading across the UK.

The US icon took to Twitter on Tuesday night (May 6) to say that her last minute preparations were going well - apart from the getting sleep part.

Perry wrote: "Twas the night before #ThePrismaticWorldTour when all through Belfast, not a creature was stirring not even one Katycat. The outfits were...

"Laid out, all sequins in place, the wigs were all set...ready to kick ball change! NOW GO TO SLEEP (I'm yelling at the both of us)."

Perry's tour meanwhile comes in promotion of her 2013 album 'Prism'.

The chart-topping record spawned such singles as 'Roar' and the Juicy J collaboration 'Dark Horse'.

Watch Katy Perry's recent videos below: