Johannesburg - President Barack Obama will make a special effort to lay the groundwork for more aid to Africa, and especially South Africa, during his short stay in Johannesburg and Cape Town.
He has arrived at a time when South Africans are preoccupied with the health of former president Nelson Mandela, who remains in critical condition in hospital.
While in Senegal, Obama said that Washington had a "moral imperative" to help the
world's poorest continent feed itself.
Just before departing from Dakar, Obama met farmers and local
entrepreneurs to discuss new technologies helping to raise agricultural output
in West Africa, one of the world's most under-developed and drought-prone
White House officials hope Obama's three-nation tour of Africa - his first
substantial visit to the continent since taking office in 2009 - will
compensate for what some view as years of neglect by America's first black
The US realised a while ago that it was ceding its position to the Chinese, who were making deeper inroads in the continent.
Beijing has surpassed Washington as Africa's largest trading partner.
The pressure increased when Chinese president Xi Jinping decided to visit Africa as part of his first trip abroad in March, shortly after becoming the leader of the world's second-largest economy.
While Western nations remain the lifeblood of African development, through aid programmes and trade, the Chinese have been pouring in foreign investment with no political conditions.
Even the new African Union headquarters in Addis Ababa is Chinese built.
Most of the world's fastest-growing economies have a presence on the continent.
With many American businesses believing Africa's boom is just around the corner, there is increased pressure on the US administration to have a policy conducive to commerce.
Trade Minister Rob Davies told reporters earlier this week: "Africa has come to a point in its development where it is beginning to be viewed by key partners as an important trade, investment and economic partner.
"We are moving away from the old relationship.
"South Africa is a very pivotal country.
"We are the most industrialised country in Africa," said Davies, stressing his country's role as a "gateway" to the rest of the continent.
Jeffery Nemeth, the head of the US Chamber of Commerce in South Africa, believes Obama's visit is vital to building up a stronger, more-committed relationship to Africa.
According to the International Monetary Fund, gross domestic product growth is forecast at 5.4% for sub-Saharan Africa in 2013 and 5.7% in 2014.
"The president's visit is a very key visit.
"Africa is the next global economic success story and South Africa plays a key role in Africa fulfilling that vision," said Nemeth.