WASHINGTON (Reuters) - Foreign aid may provide the best value for money spent by the U.S. government, Bill and Melinda Gates said Tuesday, but few seem to know it.

Microsoft founder Bill Gates delivers a speech during a dedication ceremony for the Gates Center for Computer Science at Carnegie Mellon University in Pittsburgh, Pennsylvania September 22, 2009. REUTERS/Chris Wattie

They launched a new project to try to publicize some public health successes in foreign aid, to encourage the U.S. and other governments to keep giving money.

“Dollar for dollar, global health is America’s best investment for saving lives,” Gates told reporters. “U.S.-supported global health programs are saving and improving the lives of millions of people.”

Gates, the billionaire Microsoft founder who retired in 2008, has given millions of his own money to programs such as the Global Alliance for Vaccines and Immunization or GAVI and the Global Fund for AIDS, Tuberculosis and Malaria.

But he said government money is vital, too, and a new website, www.livingproofproject.org, shows it is working, he said.

Gates’s wife Melinda, who with Gates heads the Bill and Melinda Gates Foundation, said she helps check up on money that has gone toward helping causes -- and been pleasantly surprised.

“When we make an investment we are going to go back and make sure did it work. We see that these things are working,” she said. “We realize that we are seeing a lot of hope on the ground. The hope is really palpable.”

Gates said he wanted to thank taxpayers and to ask the administration of President Barack Obama, along with Congress, to do more.

“U.S. support has already helped to reduce deaths of young children by more than 50 percent in the past 50 years. If we keep up our commitment, it’s possible to cut child mortality in half again,” Gates said.

“What’s more, we can do it with proven interventions that already exist.”

This includes the distribution of AIDS drugs by the President’s Emergency Plan for AIDS Relief or PEPFAR, launched in 2003, a Global Fund project to distribute mosquito nets and insecticides to fight malaria, and the distribution of vaccines to prevent diarrhea and pneumonia by the GAVI Alliance.

“I think a little does go a long way. But a lot more is needed,” Gates said.

“We still have 4 million children who die in the first week of life,” Melinda Gates added. Simple education programs can prevent many of these deaths, she said.

The efforts are bipartisan and not political, they said.

“There have been people in both parties who have been willing to take the risk. So far it hasn’t been that one party is for saving babies’ lives and another party has taken a position against that,” Bill Gates said.

“We want to make sure these things don’t get cut just because people don’t understand the effect they are having,” Melinda Gates said. The money does not always disappear to “dictator’s mansions,” Bill Gates added.