Obama was due to travel on to South Africa on Friday, but his plans could change should the country be plunged into mourning before he arrives on the second leg of a tour of a continent where he has deep ancestral roots.
White House officials have declined to comment on contingency plans for the trip, which is also scheduled to include a visit to Tanzania, but behind the scenes they were working to respond to various possible scenarios.
Obama and his wife Michelle arrived at Senegal’s presidential palace, where the presidents will hold a press conference, before the US leader heads to the Supreme Court in Dakar to discuss the rule of law.
Washington is keen to highlight Muslim-majority Senegal as an example of democracy and good governance in a corner of Africa plagued by instability and the threat of Islamic extremism in neighbouring Mali.
Then, in a moment of high symbolism, Obama, America’s first black president, will take a ferry to Goree Island off the Senegal coast, a memorial to the hundreds of thousands of Africans claimed by the slave trade.
In a “full circle” moment of history, Obama, the son of a Kenyan father, and his wife Michelle, the descendent of slaves, will acknowledge a dark period of American and African history which still resonates today.
“There’s this link between Obama, an American originating from Africa through his father, and his wife, an African-American originating from Africa through her ancestors,” said House of Slaves curator Eloi Coly.
“I think with all these ingredients gathered together, this visit by the Obamas should be very special.”
White House spokesman Jay Carney said that the visit would be an important moment.
“A visit like this by an American President, any American President, is powerful,” he told reporters.
“I think that will be the case when President Obama visits and I’m sure particularly so, given that he is African-American.”
The US president’s arrival in Africa came at a delicate time as the world prepared to say a farewell to Mandela.
Napilisi Mandela, an elder in Mandela’s clan, told AFP that the former South African president was on life support, and South African President Jacob Zuma called off a scheduled trip to Mozambique.
Obama and Mandela met in 2005, when the former South African president was in Washington, and Obama was a newly elected senator, and the two have spoken several times since by telephone.
But the long awaited prospect of a public appearance between the first black presidents of South Africa and the United States is now impossible.
Obama claims a spiritual connection to Africa, but a crush of international crises in his first term thwarted his hopes to travel extensively on the continent. He did manage a short trip to Ghana in 2009.
His tour is designed to highlight Africa’s emerging economic potential and growing middle class, as well as youth and health programs, and to emphasise US engagement in a region benefiting from a wave of Chinese investment.
“We are not too late,” said Carney, pointing out that although Obama had been kept away, Vice President Joe Biden visited Africa in the first term, and there were also wide ranging diplomatic efforts by the administration on the continent.
But there has been disappointment in Africa, after Obama’s 2008 election caused euphoria and an expectation that he would put Africa policy at the top of his agenda.
There is one glaring missing stop on Obama’s itinerary: Kenya.
Officials said that the indictment of Kenyan President Uhuru Kenyatta at the International Criminal Court in The Hague, over previous election violence, made it politically impossible for Obama to stop by on this tour.