Johannesburg, South Africa (CNN) -- President Barack Obama held a town hall meeting Saturday with a group of young people in the Soweto section of Johannesburg, with video links to similar groups in other cities in Africa.
Here are five things that he said in response to questions from the participants in a format he called "a little humbling" but energizing. CNN Johannesburg correspondent Nkepile Mabuse moderated the town hall.
Praise for Mandela
Obama paid homage to former South African President Nelson Mandela, the 94-year-old founding father of the country's modern democracy who is in critical condition in a Pretoria hospital. "Obviously, he is on our minds today, and we join the people of the world in sending our prayers to Madiba and his family, because he still inspires us all," Obama said, referring to Mandela by his clan name.
Obama noted that Mandela held on to his optimism during his 27 years in prison under South Africa's apartheid regime, and he urged his audience to learn from that. "There will be time to test your faith, but no matter how old you grow, I say ... don't lose those qualities of youth: your imagination, your optimism, your idealism, 'cause the future of this continent is in your hands, and if you keep your head pointed toward the sun, and you keep your feet moving forward, I promise you will have no better friend and partner than the United States of America."
Mandela showed that "through a commitment to the constitution and rule of law and equal treatment for all people that a country can prosper despite a tragic history."
A bright view of Africa's future
Africa's role in the world economy as a provider of raw materials to other parts of the world dates back to colonial days and must be changed, Obama said. Though foreign aid remains critical in some parts of the continent, "It is very clear that people want to break out of a dependency trap. The idea is not that Africa should be the ward of some other country. What we need is an Africa that's building, manufacturing, creating value, inventing and then sending those products around the world and receiving products in return. ... If we do that, there's no reason why Africa cannot succeed."
Progress against terrorism
Though "some progress" has been made in dealing with extremist groups, "the problem has metastasized" to include more regional terrorist organizations such as Boko Haram in Nigeria, Obama said. "Though they may not have the same transnational capacity that some of the earlier organizations did, they're doing great harm in Africa and in the Middle East and in South Asia."
The terrorist threat affects more than Western countries, he said. "The number of people killed by terrorist attacks in Africa or South Asia far outstrips deaths by Westerners," he said. "This is not just a problem for us; this is a problem for everybody."
Terrorism is more likely to emerge in countries that are not delivering for their people, "and where there are areas of conflict and underlying frustrations" that have not been adequately dealt with, he said.
He cited responsive governance and strong democratic institutions as bulwarks against terrorism taking root. "They're the most important defense against terrorism."
Obama rejected "this notion that we want to somehow expand our military reach," citing the end of the war in Iraq and plans to end the war in Afghanistan as evidence. "This idea somehow that we want to get more involved militarily around the world is simply not true," he said. "First of all, it costs a lot of money, and the United States -- just like every country around the world -- has to think about its budget. And where we intervene, oftentimes it's not very effective because, unless you've got a local population that is standing up against terrorism, we end up being viewed as interlopers and intruders."
He said he wants the African Union and other regional organizations to beef up their capacity to send peacekeepers "to nip terror cells that may be forming -- before they start and gain strength."
The United States, he added, can provide advice, training and, in some cases, equipment.
Global warming looms
The world's biggest environmental challenge is climate change, Obama said, adding that carbon emissions are warming the planet and threaten to cause the problem to spin out of control. "We are going to all have to work together to find ways in which, collectively, we reduce carbon," but wealthy countries must do more than companies that are still developing, he said. "Obviously, they shouldn't be resigned to poverty simply because the West and Europe and America got there first. That wouldn't be fair, but everybody's going to have to do something."
If, however, everyone buys cars, installs air conditioners and moves into big houses, "the planet will boil over unless we find new ways of producing energy," he said.