Geneva: The United Nations on Wednesday endorsed male circumcision as a way to prevent HIV infections in heterosexual men and said it should be made more easily available in African countries.

Two UN agencies, the World Health Organisation (WHO) and UNAIDS, backed recent research showing that removing the foreskin of the penis can more than halve men's vulnerability to the virus causing AIDS from having sex with HIV-infected women.

They said that countries with high rates of heterosexual HIV should urgently improve access to male circumcision, giving priority to sexually active young men, while continuing to promote condom use and encourage regular testing.

"These recommendations represent a significant step forward in HIV prevention," said Kevin de Cock, the WHO's director for HIV/AIDS programs, pointing to big potential gains in places where male circumcision is rarely practiced.

"Scaling up male circumcision in such countries will result in immediate benefit to individuals. However, it will be a number of years before we can expect to see an impact on the epidemic," he said.

Of the 40 million people worldwide infected with the human immunodeficiency virus, 25 million live in sub-Saharan Africa, where the disease is spread mostly through heterosexual sex.

The WHO and UNAIDS said increasing male circumcisions could prevent 5.7 million sub-Saharan African men from contracting HIV over the next two decades, and save three million lives.

Some 30 per cent of men worldwide are currently circumcised. The practice occurs for religious reasons among Jews and Muslims and in others for hygiene purposes, generally among infant boys.