The United Nations on Friday urged countries to focus on the roots of the AIDS epidemic and draw on a panoply of tried-and-tested tools to help prevent HIV spreading among groups of people who most at risk.

"There is no single magic bullet for HIV prevention, but we can choose wisely from the known prevention options available so that they can reinforce and complement each other," said Peter Piot, the outgoing executive director of UNAIDS.

Launching a report ahead of World AIDS Day on December 1, Piot called for understanding how the most recent HIV infections were happening and why they occurred in the first place.

"Not only will this approach help prevent the next 1,000 infections in each community, but it will also make money for AIDS work more effectively and help put forward a long term and sustainable AIDS response," he said.

Unlike previous years, UNAIDS did not give any fresh figures for the number of infections and deaths ahead of World AIDS Day, saying the relevant data had not yet been amassed.

Statistics published ahead of the International AIDS Conference in Mexico City in August say that around 33 million people had the human immunodeficiency virus (HIV) in 2007, in a range of 30.3 to 36.1 million.

Around 2.7 million people became infected, or on average around 7,500 people per day, while deaths were estimated at around two million.