The decision by the Group of Eight (G8) summit was criticised as too stingy by major charities but cautiously welcomed by Irish rock star activists Bono and Bob Geldof who had staged anti-poverty concerts worldwide in the last week.
British Prime Minister Tony Blair, the summit host, said the aid increases, combined with debt write-offs, a push for universal access to AIDS treatment and other steps, amounted to "real and achievable progress".
His announcement followed three days of talks at the Gleneagles golf resort, overshadowed by bomb attacks in London on Thursday, with the leaders of Canada, France, Germany, Italy, Japan, Russia and the United States.
But he acknowledged that campaigners would be disappointed by the G8's failure to set a target date for eliminating European and US export subsidies that undercut African farmers.
"We do not, simply by this communique, 'make poverty history'," he said, borrowing the slogan of a celebrity-backed campaign in Britain to raise awareness of the plight of Africa's poor.
"But we do show it can be done and we do signify the political will to do it."
A summit statement said commitments from G8 and other donors would mean an increase in aid to Africa by $25 billion a year by 2010, more than doubling assistance to the continent compared with 2004.
The statement, citing an estimate from the Organisation for Economic Cooperation and Development, added that donor pledges to official development assistance for all developing countries would increase by around $50 billion a year by 2010.
The package included up to $3 billion for Palestine, although Blair did not give a timeframe for releasing the aid, saying only that the G8 countries would deliver it in the years to come.
"We do not, simply by this communique, 'make poverty history'. But we do show it can be done and we do signify the political will to do it"
British prime minister
Palestinian officials said that they expected much of the money to go to job creation and infrastructure projects in Gaza, where unemployment runs at more than 50%.
The $25 billion pledge for Africa was contained in a report by the Commission for Africa, a panel set up by Blair and announced amid great fanfare in March, that also included fellow commissioners, Geldof and South African Finance Minister Trevor Manuel.
President Olusegun Obasanjo of Nigeria spoke later of "encouraging signs" that "the continent's problems are going to be addressed realistically and effectively by the G8".
He was joined at the summit by counterparts from Algeria, Ethiopia, Ghana, Senegal, South Africa and Tanzania.
Geldof said it was too early to say whether the summit outcome had been historic.
"The summit at Gleneagles is a qualified triumph," said Geldof. "Today gives Africa the opportunity of beginning to end poverty over the next 10 years."
"G8 leaders have promised $50 billion more in aid by 2010. While aid increases are welcome, this is too little, and it's too late for the 50 million children who will die between now and 2010"
However, organisations such as the World Development Movement, Oxfam International and Action Aid expressed strong disappointment with the aid pledges and other steps.
They said the increase would bring development assistance to just under $130 billion in the next five years, short of the UN Millennium Development Goals of $180 billion.
The UN goals, approved in 2000, call for the proportion of people living on less than a dollar a day to be halved by 2015.
"G8 leaders have promised $50 billion more in aid by 2010. While aid increases are welcome, this is too little, and it's too late for the 50 million children who will die between now and 2010," Action Aid said in a statement.
"If they are serious about making poverty history, they should announce $50 billion in aid now, not in five years' time," it said.
"Moreover, if you do your sums, less than half of this funding is genuinely new money," it said.
Blair said the package also included "universal access to AIDS treatment", but Action Aid cautioned that there remain big questions about how that will be funded.
The charities also said they were disappointed that the G8 leaders failed to go beyond the $40 billion in immediate debt write-offs for the world's poorest 18 countries, which their finance ministers had agreed last month.