Christina Aguilera feels guilty about not doing enough charity work.

'The Voice' judge spent an emotional few days in Kigali, Rwanda, on a hunger relief mission this June, where she visited refugee camps and was stunned by what she witnessed there.

Since returning to the US, the 32-year-old singer hasn't been able to get the image of the extreme poverty out of her mind and is desperate to do more to help.

Christina told People magazine: ''This trip came at a time when I really needed to step away and connect with bigger issues in the world, [and] this trip really touched me in a way I never felt before. I came home and really wondered about why some people are born to some situations and others are born in a different place.

''I had to come to terms with a little guilt even for coming home and not doing more. The people of Rwanda touched me in a way I cannot express or put into words. They are in a place that needs our help and I am so proud of the work that we are doing there.''

Christina is backing the Yum! Brands World Hunger Relief effort and is an Ambassador Against Hunger for the UN World Food Programme.

The blonde claims she was inspired by her five-year-old son Max - her child with her ex-husband Jordan Bratman - to take part in the projects, and says meeting Rwandan children was an especially heart-wrenching for her as a mother.

She explained: ''After the birth of my son, I started looking into causes that touched me as a mother and I was so moved by the work the World Food Programme and Yum! did.

''As a mom, to know that there are kids that go to bed hungry is just not acceptable. Food is a human right in my mind and knowing that I can help means so much. In Rwanda, we visited a school. The kids walk approximately two miles to get there, not only to learn but for many this is their only meal of the day.''