Speaking in Liberia where he is to attend a UN meeting, Cameron called for the next wave of international development targets to focus on extreme poverty.
The prime minister also insisted bolstering security and civil structures was crucial, alongside aid measures.
Cameron was speaking after a surprise visit to Libya
The high-level panel, which Cameron is jointly chairing with the country's president Ellen Johnson-Sirleaf, is part of the process to decide what targets to bring in after the Millennium Development Goals expire in 2015.
Speaking to reporters this morning, Cameron said: "Liberia is a country that was absolutely devastated by conflict and civil war.
"It is now recovering but there is still desperate poverty. I think it is very important we keep a focus on eradicating extreme poverty.
"Here in Liberia, one in 10 children do not make it to the age of five. But I also think it is important we look at those things that keep countries poor.
"Conflict, corruption, lack of justice, lack of the rule of law. These things matter as well as money."
Cameron intends to raise aid spending to 0.7% of UK GDP at a time when other government departments are facing heavy cuts.
Last year he was urged to scrap the "arbitrary" target by members of his own party.
Gerald Howarth, a defence minister until the reshuffle, said diverting money to aid from the defence budget would have a serious effect on Britain's influence in the world and claimed the policy was only being implemented to "mollify" the Lib Dems.
Former chancellor Lord Lawson, Tory funder Lord Ashcroft and former defence secretary, Dr Liam Fox, have also spoken out against the target.
The prime minister was forced to concede yesterday that the defence budget could face more cuts in 2015-16, while the international development budget is protected.
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