Rich nations need to increase their funding to poor countries if they are to meet the aid commitments they have set, a report says.
Most of the world's poorest countries are in Africa
The Organisation for Economic Co-operation and Development (OECD) said the target of increasing aid to $130bn by 2010 might be missed.
A commitment to double aid to Africa was also off course, it added.
The report said the US gave most aid - though Norway and Sweden donated most as a proportion of national income.
LARGEST GIVERS OF OFFICIAL DEVELOPMENT ASSISTANCE (BY VOLUME) IN 2005
1. US - $27.622bn
2. Japan - $13.147bn
3. UK - $10.767bn
4. France - $10.06bn
5. Germany - $9.92bn
In 2005, $106.8bn was given in aid and debt relief by the 22 countries of the OECD's Development Assistance Committee.
The OECD said that aid funding had been rising by 5% per year, but that this would have to rise to 11% every year from 2008 to 2010 to hit the $130bn target.
Iraq was the biggest recipient, receiving $12.9bn, boosted by massive debt relief.
The OECD said its report highlighted how important aid was to many countries, with nations such as Liberia and the Solomon Islands relying on it for more than half of their gross national income (GNI).
LARGEST GIVERS OF OFFICIAL DEVELOPMENT ASSISTANCE (BY % OF INCOME) IN 2005
=1. Norway - 0.94%
=1. Sweden - 0.94%
=3. Luxembourg - 0.82%
=3. Netherlands - 0.82%
5. Denmark - 0.81%
It also said that countries dependent on aid might have governments less responsive to their citizens and less likely to impose taxes.
The organisation added that as economies in the Far East grew, aid sent there was expected to decline.
It also said that while the amount of aid given was vital, it also needed to be distributed more effectively - with both donors and recipients being made fully accountable.
"There is a gap of billions of dollars between what donors countries report as aid and what recipients see and control through their own budgets," it said.
The OECD report said Luxembourg gave $550 per person, whereas nine of the 22 donor nations gave less than $100.
In 2005, leaders at the G8 summit in Scotland pledged to cancel the debts of many of the world's most poorest countries, most of which are in Africa.