JOHANNESBURG, South Africa - President Obama today tried to downplay expectations that he will meet with Nelson Mandela in the coming days, telling reporters, "I don't need a photo-op" with the ailing civil rights icon.

"The last thing I want to do is to be in any way obtrusive at a time when the family is concerned about Nelson Mandela's condition," the president told reporters traveling aboard Air Force One en route to Johannesburg.

"I've had the opportunity to meet with him. Michelle and the girls had an opportunity to meet with him. Right now, our main concern is with his wellbeing, his comfort, and with the family's wellbeing and comfort," he said.

Obama and Mandela have met only once in person, during a spontaneous meeting in Washington in 2005, when Obama was a senator. Michelle Obama and daughters Malia and Sasha met Mandela in 2011.

It was widely speculated that Obama would meet with Mandela for the first time as president during his weeklong trip to Africa, in what would be a deeply symbolic face-to-face encounter.

The president did not rule out the possibility of a meeting. "We'll see what the situation is when we land," he told reporters.

"I think the main message we'll want to deliver if not directly to him but to his family is simply our profound gratitude for his leadership all these years and that the thoughts and prayers of the American people are with him, and his family, and his country. I think in that sense, the sentiment of Americans is universally shared around the world," he said.

The White House is deferring to the Mandela family to decide if he is up for a visit from Obama.