Katy Perry in tears after receiving UNICEF award from idol Hillary Clinton

Katy Perry broke into tears when Hillary Clinton surprised her with her appearance, presenting the pop star with an award for her charitable efforts at yesterday's UNICEF Snowflake Ball.

Clinton, who lost the recent election to Donald Trump, gave Perry the Audrey Hepburn Humanitarian Award for her charitable efforts with the organisation.

She described Perry as someone who has "the spirit and the energy and the compassion that Audrey Hepburn brought to her work from UNICEF".

Clinton also said Perry's lyrics "remind us when you get knocked down to get back up".

Perry was a big supporter of the Democrat, who won the popular vote, and even campaigned for her.