Senators voiced concern Tuesday that the United States has lost influence with African governments as China has emerged as the continent's main trading partner and a major source of investment for infrastructure development.

Sen. Chris Coons, D-Del., who chairs the Senate Foreign Relations African affairs subcommittee, said the U.S. goal of promoting open societies in Africa was being challenged by China offering no-strings-attached investment for repressive regimes.

Coons said about 70 percent of Chinese assistance to Africa comes in the form of roads, stadiums and government buildings, often built with Chinese material and labor, while 70 percent of U.S. government spending there goes toward crucial but less visible support for people, particularly to fight AIDS, malaria, tuberculosis and other diseases.

"We may be winning the war on disease, while losing the battle for hearts and minds in Africa," Coons told a subcommittee hearing on China's role in Africa and its implications for U.S. policy.

Coons' comments echo a common theme among U.S. policymakers, that China's rise as an economic and political power challenges America's global predominance.

Lawmakers criticized China's state-backed support for governments with poor human rights records.

"China is interested in their own goals and has very little concern about the governance of the countries that they deal with," Sen. Ben Cardin, D-Md.

But experts told the panel that by supplying loans for infrastructure development, often in return for exports of commodities China needs for its own economic growth, the Asian power was responding to what African governments want, and filling a need unmet by Western nations.

David Shinn, adjunct professor at George Washington University and former U.S. ambassador to Ethiopia and Burkina Faso, gave the example of Angola, which had unsuccessfully sought Western investment after its civil war, and instead turned to China, which helped develop infrastructure in return for the promise of oil exports.

Deborah Brautigam, a professor at American University, said Chinese investment was often perceived to have a negative impact on human rights and democracy, principally because of Beijing's support of Zimbabwe and Sudan. But she said there was no evidence that political rights and freedom had declined in general across the continent.

Shinn, however, believed Chinese investment had to some degree undermined Western goals of promoting democracy, good governance and human rights. He said there also was evidence of Chinese companies importing technology to enable certain governments, such as Zimbabwe and Ethiopia, to restrict the flow of information on the Internet.

He said China passed the United States as Africa's most important trade partner in 2009. In 2010, China-Africa trade totaled $127 billion, compared with U.S.-Africa trade of $113 billion. China also possibly is investing more in Africa than any other single country, he said.

Stephen Hayes, president of the Corporate Council on Africa, a group representing U.S. businesses in Africa, told the hearing that U.S. embassies should do more to advance American commercial interests. He also wanted the U.S. aid program to promote U.S. businesses as a partner in African development.