US President George W Bush has pledged $15bn over the next five years to fight Aids.

In his State of the Union address, Mr Bush said the money would provide drugs for two million people with the disease and help to prevent seven million new infections.

The money will be targeted at projects in sub-Saharan Africa, where as many as one in three adults in some countries have HIV.

Seldom has history offered a greater opportunity to do so much for so many President George W Bush

The president said his Emergency Plan for AIDS Relief would also help those Caribbean countries worst affected by the disease.

Most of the fund's $15bn budget will be earmarked for use in Botswana, Ethiopia, Guyana, Haiti, Ivory Coast, Kenya, Mozambique, Namibia, Nigeria, Rwanda, South Africa, Tanzania, Uganda, and Zambia.

More facilities

According to the White House, the money will be given to private groups and governments to put in place a comprehensive system for diagnosing, preventing and treating AIDS.

The money will pay for new laboratories at central hospitals and specialist doctors and nurses.

It will also fund new satellite clinics to ensure that people living in remote areas of these countries can receive treatment and health information.

Mr Bush said the reduced cost of anti-retroviral drugs offered an opportunity to save millions of lives.

"Aids can be prevented. Anti-retroviral drugs can extend life for many years.

"And the cost of those drugs has dropped from $12,000 a year to under $300 a year - which places a tremendous possibility within our grasp."

He added: "Seldom has history offered a greater opportunity to do so much for so many."

Mr Bush described his relief plan as a "work of mercy" which is designed to meet "a severe and urgent crisis abroad".

He added: "This comprehensive plan will prevent seven million new Aids infections... treat at least two million people with life-extending drugs... and provide humane care for millions of people suffering from Aids, and for children orphaned by Aids."

An estimated 40m people are infected with HIV/Aids. Some 20m people are believed to have died from the disease so far. It has left 14 million orphans worldwide.