But a congressional investigator said a study found that the policy often confused AIDS workers and may have interfered with prevention efforts.

"We are teaching young men a lot of important lessons about respecting women," U.S. Global AIDS Coordinator Mark Dybul told the hearing of the U.S. House of Representatives Subcommittee on National Security, Emerging Threats and International Relations.

The legislation that funds the President's Emergency Plan For AIDS Relief, or PEPFAR, requires that 33 percent of all money spent on prevention in 2006 must be used to promote abstinence. This has been controversial, with some groups that are funded by PEPFAR complaining they cannot provide services because of the restriction.

Dybul defended the ABC policy - which stands for Abstain from sex before marriage, Be faithful, and use Condoms - as the best way to achieve this. "The data for ABC are overwhelming," Dybul said.

The AIDS virus infects close to 40 million people globally and has killed nearly 25 million.

CARE says that worldwide, 80 percent of women newly infected with HIV are monogamous, but their husbands or partners are not. In sub-Saharan Africa, women make up 60 percent of those infected with HIV.

Experts agree a big part of the problem is that women globally are unable to refuse sex and are unable to force men to be faithful or to use condoms.

Dybul said PEPFAR was addressing this.

"If men learn ABC, if men practice ABC, gender issues become easier to deal with," Dybul said. "Men will negotiate."

He described a program in Namibia that aims to stigmatize older men, called "sugar daddies," who prey sexually on young girls. "Sometimes stigmatization is a good thing," he said.

He also defended the use of religious pressure.

"If these folks are from a Muslim culture or orthodox culture and if there is something there that stresses monogamy or faith or not lying, for goodness sakes use those arguments," Dybul said. "We have got to stop the spread of HIV."

Connecticut Republican Rep. Christopher Shays, who held the hearing, said perhaps the problem simply lies in the way the funding legislation is written - it requires that 33 percent of prevention funds spent in 2006 be spent promoting abstinence.

"The program you just described, teaching a different behavior, I think there is a logic to that," Shays said. "But there is no logic to me that says one-third (of funding) should go that way."

President George W. Bush has asked Congress for $4 billion to fight AIDS in 2007, a big increase from the $3.2 billion budgeted this year and by far the biggest amount spent by any government.

David Gootnick, director of international affairs and trade at the General Accountability Office, said a GAO study showed that abstinence-until-marriage spending requirement "presents challenges to most" of the groups trying to spend that money.

"About half of the country teams indicated that adherence to the spending requirement can undermine the integrated nature of HIV/AIDS prevention programs," Gootnick told the hearing.