A $15bn scheme to fight HIV and Aids will include the distribution of condoms and generic drugs, in two big changes to US policy.

The commitment to worldwide Aids relief was outlined by US President George W Bush in his State of the Union address on Tuesday.

Mr Bush said the money would build on existing aid schemes

But details unveiled later may upset the president's supporters in two political power-bases, correspondents say.

Conservatives say abstinence should be the key to stopping the spread of HIV, while pharmaceutical giants have opposed exports of generic copies of their Aids drugs.

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

He said the $15bn investment would be targeted towards projects in sub-Saharan Africa - where in some countries one in three adults are infected by HIV - and the Caribbean.

Click here to watch the State of the Union address with clickable highlights

The US money would provide drugs for two million people with the disease and help to prevent seven million new infections, he said.

Anthony Fauci, head of the National Institute of Allergy and Infectious Diseases, said generic Aids drugs manufactured by Cipla, an Indian company, will be among those recommended to the 14 nations getting help.

Just last month, the Bush administration blocked plans by the World Trade Organisation to allow developing countries to buy cheap drugs, saying a deal would allow too many patents to be ignored.

Condom criticism

Mr Fauci said condom distribution would be part of the prevention component - but so would abstinence education.

Correspondents say Christian conservatives - a pillar of Bush's domestic support - believe that distributing condoms promotes promiscuity, and have emphasised abstinence.

Such groups criticised Secretary of State Colin Powell when he told a young audience he encouraged the use of condoms among sexually active people rather than urging abstinence.

Mr Fauci told reporters that emphasising either component - condoms and abstinence - unfairly skewed broad prevention policy.

"There are 12 points of prevention," he said, including preventing mother-to-child transmission, media campaigns and making sure blood used in transfusions is safe.

Officials insisted that the president's proposal for cheap drugs and condoms had little to do with politics.

Jendayi Frazer, the top Africa adviser on the White House's National Security Council, said: "It derives from his sense of the need to preserve human dignity."