Bono has told World leaders in Switzerland that the Aids epidemic is a global emergency.
The U2 singer is speaking at the World Economic Forum - an annual brainstorming session on world poverty, disease and climate change.
British Prime Minister Tony Blair and former US President Bill Clinton are also attending the forum.
Bono said: "I suppose my job as a rock star and activist is to bring applause when people get it right and make their lives a misery when they don't."
"I think I have some use here to try to encourage people to take some unpopular decisions at home and do the right thing on the global stage. These are expensive choices people have to make if they want to do the right thing for Africa."
