Leaders of the G8 developed nations have pledged $20bn (£12bn) for efforts to boost food supplies to the hungry, on the final day of a summit in Italy.
The investment, which is $5bn more than had been expected, will fund a three-year initiative to help poor nations develop their own agriculture.
US President Barack Obama said the issue of food security was of huge importance to all nations in the world.
Richer nations had a moral obligation to help poorer nations, he said.
Mr Obama added that the G8 nations had agreed to commit $15bn for the new initiative going into Friday's meeting, but had then promised an additional $5bn in "hard commitments" during the talks.
"We do not view this assistance as an end in itself," he said.
"We believe that the purpose of aid must be to create the conditions where it's no longer needed, to help people become self-sufficient, provide for their families and lift their standards of living."
Mr Obama, who has relatives in Kenya, said he had drawn on his family's personal experience in his discussions with other world leaders.
The US will reportedly contribute some $3.5bn to the programme.
Mr Obama met representatives of Angola, Algeria, Nigeria and Senegal in L'Aquila, where the summit is being held. He will also meet Pope Benedict XVI in Rome before embarking on an African tour later on Friday.
African leaders had earlier urged G8 nations to live up to past aid pledges.
BBC economics correspondent Andrew Walker says the idea is to put more emphasis on helping people feed themselves.
That is to be achieved with more investment in the agriculture of developing countries, and the G8 nations - Britain, Canada, France, Germany, Italy, Japan, Russia and the US - will provide significant resources, our correspondent adds.
However, although the total amount of overseas development aid (ODA) was increased in 2008, the rich countries are still behind on their target to double aid that was made at the G8 Gleneagles Summit in 2005 - and Italy is among the laggards.
Not all the money pledged to the agriculture initiative at the summit will be new funding.
Kanaya Nwanze, president of the International Fund for Agricultural Development, told the BBC that he welcomed the announcement of more investment in agriculture in the developing world.
"It is time for us to switch because food security is not just food aid," he said.
"It is the ability of people to produce food locally and for them to be able to have access to local markets."
Ethiopian Prime Minister Meles Zenawi, who also attended Friday's talks, told Reuters news agency beforehand that the key message from African nations was that the G8 had to live up to its commitments.
Aid organisations have criticised some members for failing to deliver on the promise made at the 2005 G8 summit to increase annual aid levels to sub-Saharan Africa by $25bn by 2010.
Italy, the present summit host, has come under particular pressure for cutting, rather than increasing, aid this year.
Prime Minister Silvio Berlusconi has said the global economic crisis and Italy's mounting debts are responsible for a delay in Rome meeting its promises.
