World leaders today agreed a $60 billion pledge to fight Aids and other diseases in Africa and restated broader promises to double development spending.
"We are aware of our responsibilities and will fulfil our obligations," German Chancellor Angela Merkel, hosting Group of Eight leaders, said on the final day of the summit.
But campaigners complain that rich nations have fallen behind on commitments made to double development aid at a summit in 2005 in Gleneagles, Scotland, and many were unimpressed with the deal.
President Bush missed some of the morning sessions at the summit because of a stomach ailment.
Leaders agreed to earmark $60 billion to fight AIDS, malaria and tuberculosis, global diseases that have devastated African peoples and their economies.
But the declaration set out no specific timetable, saying the money would flow "over the coming years". Moreover, it did not break down individual countries' contributions.
Campaigners for Africa say the pledge is made up largely of money that has already been announced, including $30 billion from the United States.
Steve Cockburn of the Stop Aids Campaign said the pledge falls short of UN targets that oblige G8 nations to spend $15 billion per year to combat Aids alone through to 2010.
Leaders also reiterated an overall pledge made in 2005 to raise annual aid levels by $50 billion by 2010, $25 billion of which is for Africa.
"The important thing is that we have recommitted ourselves to all the commitments we made a couple of years ago," said British Prime Minister Tony Blair, who hosted the 2005 meeting.
Mr Blair and Ms Merkel stressed they expect African leaders to fight corruption and boost transparency so donors can track aid as leaders of six African nations joined the G8 heads on Friday for their discussion on aid.
The major powers at the summit are deadlocked on a compromise on the breakaway Serbian province of Kosovo, with Russia resisting the terms of a French plan to delay a UN vote on its independence.
Russia is opposing Western efforts to adopt a UN resolution that would clear the way for independence, and France has suggested a six-month delay in any vote to find more time for a deal.
Officials were also discussing Iran and were likely to confirm plans to back "further measures" - in other words more UN sanctions - against Tehran if it continues to reject UN demands to halt uranium enrichment in its nuclear programme.