President Barack Obama is visiting Tanzania, on the last leg of his three-nation African tour, which has so far taken him to Senegal and South Africa.
The US leader is expected in Tanzania on Monday, hot on the heels of Chinese President Xi Jinping, who included Tanzania on his first overseas tour in March.
There, Obama will hold talks and a news conference with President Jakaya Kikwete and visit the Ubungo power plant, after unveiling a new $7bn programme to enhance Africa's electric power networks.
He will also lay a wreath at a memorial to those killed in the US embassy bombing in 1998.
His wife Michelle Obama will take part in a First Ladies forum hosted by her predecessor in the role, Laura Bush.
Obama warned on Sunday that Africa could only fulfill its destiny with leaders who strive to improve the lives of their people
Talk of an economic rivalry in Africa between Washington and Beijing has been a theme of Obama's trip.
Obama spent the weekend paying homage to South Africa's former president Nelson Mandela, the political hero who drew him into politics, on an ascent that led him to become the first black president in the United States, a country, like South Africa, with a tainted racial past.
He decided not to visit the father of modern South Africa, who lies critically ill in a Pretoria hospital, out of "deference" and on the Mandela family's wishes.
However, Obama paid repeated tribute to Mandela's legacy, painting him as one of history's most important political figures.
On Sunday, Obama stood in the tiny cell once occupied by Mandela on Robben Island outside Cape Town, and took his daughters to the lime quarry where Mandela and fellow prisoners once did futile, back-breaking, hard labour.
Later, in a speech at Cape Town University, Obama decried "thugs and warlords" who hold back the promise in Africa.
In a strident call for democratic change and good governance, Obama used the political legacy of Mandela and South Africa's emergence from grim years of racist apartheid rule as proof that freedom will ultimately prevail.
"History shows us that progress is only possible where governments exist to serve their people and not the other way around," said Obama, drawing loud and prolonged cheers from his audience of more than 1,000 people.
While Africa is "on the move," progress is based on a fragile foundation, Obama said.
Former president George W. Bush, feted in Africa for his AIDS programme which saved millions of lives, is also in Africa at the same time as Obama, but it is unclear whether they will meet.
Elsewhere on the trip, during a speech made in Cape Town, Obama condemned the rule of Zimbabwe's Robert Mugabe in neighbouring Zimbabwe, where he said the "promise of liberation gave way to the corruption of power and the collapse of the economy".