Officials brush off questions over whether major meeting is in response to China's growing influence.
The United States will announce nearly $1bn in business deals, increase funding for peacekeeping and commit billions of dollars to expanding food and power programs in Africa during a summit this week, officials said.
US officials said the August 4-6 summit in Washington of nearly 50 African leaders hopes to showcase US interest in the continent through a series of government-private partnership deals to boost trade and investment.
The spread of the deadly Ebola virus in Liberia, Guinea and Sierra Leone is also a reminder of the vast development needs that persist in some of the continent's poorest countries, despite rapid economic growth and investment.
Administration officials have played down questions over whether the summit is in response to China's growing presence in the continent.
Instead, they say American interests go beyond Africa's oil and minerals, areas on which some say China is focused.
"You will see a series of announcements on agriculture and food, and power and energy," Rajiv Shah, the administrator of the US Agency for International Development (USAID), told the Reuters news agency.
"We will make big announcements that demonstrate these are big ambitions we can take on with our African partners and the private sector."
Shah said there will be new support for Power Africa, a privately funded program launched by President Barack Obama last year to install 10,000 megawatts of new generation capacity and connect 20 million new customers across Africa by 2018.
Shah said while companies pledged $7bn to the program last year, next week "there will be several billions of dollars" in new investments. The World Bank is also expected to make a major contribution, according to Bank officials.
The program is also likely to be expanded from the six nations - Ethiopia, Kenya, Ghana, Liberia, Nigeria and Tanzania- that are currently included.
| Peacekeeping boost
There will also be significant increases in private sector support for US-backed food and agricultural programs in Africa, including the New Alliance for Food Security and Nutrition, US development officials said.
Donald Kaberuka, president of the African Development Bank, said the summit represented a shift in the US-Africa relationship from a focus on aid to investment and trade.
"There are still bits of aid needed here or there but fundamentally the relationship is now defined as one of trade, investment, growth and opportunities," Kaberuka told Reuters in an interview.
"It responds to what Africans are looking for and responds to expectations of American business," he added.
The summit will include a business conference on Tuesday bringing together African leaders and American CEOs.
In other funding increases, the State Department is expected to announce a further $60m a year for peacekeeping training in six African countries, according to US officials.