"There were some serious promises made. The checks were signed but, as you know, politicians like signing checks but they don't like cashing them, " Bono told reporters.

At a meeting in 2005, the G8 group of industrialised nations agreed to cancel the debts of 18 lowincome countries and pledged to double African aid to Euro37bn by 2010.

"Two years on, it's time to take the temperature, " Bono said. "If those promises are not kept? it will make a generation of cynics."