Katy Perry has become the latest celebrity to join forces with the United Nations Children's Fund (Unicef) as a goodwill ambassador.

The Roar hitmaker announced her new philanthropic role on Tuesday (03Dec13), citing her recent trip to the impoverished nation of Madagascar as a life-changing experience that made her decide to take on the new title.

She tells the Associated Press, "It (the trip) changed my life. It really kind of reprioritised my thinking, and my whole approach on life."

The visit also served as a great inspiration for her new album, Prism.

Perry explains, "I was going through a transition in my life, where I felt like I had been suppressed and emotionally toyed with - and I went there (Madagascar), and I was like, 'I have nothing to compare my situation to'. It made me feel very grateful, but also very aware."

As the latest ambassador, the singer will focus on children and adolescents who are most vulnerable as a result of severe poverty, violence, abuse and neglect. Perry plans on making one trip a year for Unicef, and is hoping to visit Peru, Haiti, and the Philippines.

She adds, "It's nice to be able to pop the bubble that I live in and realise that the world has so many different things to offer."

Perry joins fellow celebrity Unicef ambassadors, including Selena Gomez and Sarah Jessica Parker.