U2 frontman Bono and rock band Pearl Jam performed a surprise duet on Friday at an open air concert on the sidelines of the Melbourne G20 summit, calling for an end to world poverty.

Church and aid groups joined in the protests as ministers and bankers began arriving.

Singing "Rockin' In The Free World", Bono called on 14,000 fans at the free "Make Poverty History Concert" to demand world politicians step up the fight against global poverty.

"Politicians have to do what you tell them to do. We are gonna make poverty history," Bono, a leading voice in the Make Poverty History coalition, told a cheering crowd in an amphitheatre a short walk from the G20 venue.

Aid groups protesting in Melbourne claimed the US-led war on terrorism was soaking up global aid.

"We cannot win the war on terror unless we win the war on poverty," said Rev Tim Costello, brother of Australia's treasurer and co-chairman of the Make Poverty History coalition.