"We want to dismantle long-held and often outdated notions of what it means to live, work and invest in Africa," a senior U.S. official told reporters, speaking on condition of anonymity.
Harris "believes African innovation and ideas will shape the future of the world," said the official.
Harris' trip to Ghana, Tanzania and Zambia is the latest salvo in deepening US engagement with a continent largely ignored under Republican Donald Trump - and long viewed in Washington as more of a problem area than a land of opportunity.
A senior official said the Biden administration recognizes the "strategic importance" of Africa in global issues including climate change, supply chain resilience and also as players in the United Nations.
The United States seeks to pitch itself as a better partner than China, which has invested heavily in the continent over several decades.
"We're not asking our partners in Africa to choose," said a senior official, describing the competition with China, although he added that the U.S. has "real concerns about some of China's behavior in Africa" and its "opaque" business dealings.
Harris will discuss China's engagement in technology and economic issues in Africa that concern the United States, as well as China's involvement in debt restructuring, senior U.S. officials said.
"It's no secret that we are engaged in competition with China very clearly, to compete (with) China in the long term," a senior US official said. Citing "real concerns" about China's use of loans to gain control over weak economies in Africa, the official insisted the United States is not trying to copy Beijing's methods.
Preceding Harris, who lands Sunday in Ghana for the first stop, have been trips to Africa by five of President Joe Biden's cabinet secretaries and First Lady Jill Biden.
The vice president's journey, which will take her to Tanzania on Wednesday, then Zambia on Friday, has a special poignancy. She is the first Black person and woman ever in the White House number two job and she visited Zambia as a young girl, when her maternal grandfather, who was from India, worked there.
The trip will also help her burnish her foreign policy credentials ahead of what is expected to be Biden's bid for a second term in office - with her again at his side.
Harris is due to meet with President Nana Akufo-Addo of Ghana, President Samia Hassan of Tanzania and President Hakainde Hichilema of Zambia.
Topics will include debt relief, democracy, economic growth, food security, and impacts of Russia's war in Ukraine.
A big overall focus for Harris on her trip will be youth in this rapidly growing continent, where the average age is just 19 and where an estimated one in four people in the world could be living by 2050.
Highlights will include a "major speech" to young people in Ghana and a visit there to Cape Coast Castle, once a slave trading hub. Further stops will include meetings with tech entrepreneurs, digital sector leaders, and groups advancing women in the economy.
In a reminder of the deep-rooted - and ongoing - unrest involving extremist Islamist groups, Harris will lay a wreath to commemorate the 1998 bombing of the US embassy in Dar es Salaam, Tanzania.
This report was sourced from Reuters and Agence France-Presse.