The U.S. President hosted the 'Dark Horse' hit-maker at a White House dinner to honour the 46th anniversary of the Special Olympics and admitted he felt 'grateful' she'd taken time out of her busy schedule to be there.
Introducing her on stage, Obama said: 'We have just one of my favorite people performing tonight -- Katy Perry. We are so grateful to her.
'I love Katy Perry. She is just a wonderful person,' he added.
'I've just met her mom and now I know why she is such a wonderful person, but I just want everybody to know she is on tour right now and so, for her to take time out to do this, is really special and we really want to say thank you to her for doing this.'
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And she looks great
at Obama promoting Prismatic tour