CAPE TOWN, South Africa -- It’s a long way from Washington, but President Obama and President George W. Bush could wind up seeing one another – in Africa.

The White House did not rule out a meeting between the two men when they overlap in Tanzania on Monday. Obama and his family will travel there from South Africa for the final stop of their three-country Africa tour, and Bush will be there with wife Laura for a First Ladies Summit hosted by the Bush Foundation. Michelle Obama also will participate in that event.

Though a joint appearance by the two presidents has not been scheduled, a senior administration official suggested that could change.

“I think that’s still being worked through,” deputy national security adviser Ben Rhodes said aboard Air Force One as Obama traveled from Johannesburg to Cape Town in South Africa on Sunday. “There may be something. We’ll keep you updated.”

Bush has earned widespread praise, including from Obama, for his administration’s focus on Africa and the fight against HIV/AIDS. The President's Emergency Plan For AIDS Relief – or PEPFAR – committed $15 billion to helping eradicate the disease and has been widely credited for saving up to 2 million lives.

The Obama administration has continued to fund the PEPFAR program.

“When PEPFAR was launched, the world feared for the future of this continent,” Rhodes said. “In June, the millionth baby born without HIV and AIDS was born because of PEPFAR. So what we are seeing is something that no one thought was possible turn into reality.”

In some ways, however, Obama has been dogged by the legacies Bush and former president Bill Clinton have left in Africa, where both are remembered fondly for their investments. Clinton also enjoyed a warm relationship with Nelson Mandela, Obama’s personal hero, who has been too ill to foster a similar kind of inter-personal connection with Obama.

Still, Rhodes said that the presence of two presidents from different political parties in Africa at the same time – regardless of whether they appear together – is a “powerful symbol” that “sends a very positive message that both political parties in the United States share a commitment to this continent.”