As the United States deals with the aftermath of a meeting between sitting President Donald Trump and Russia’s Vladamir Putin that has been labeled “treasonous,” former President Barack Obama prepares to deliver a speech aimed at encouraging young people to fight for a more just world.

Obama will deliver the speech—his first high profile appearance since leaving the White House—in Johannesburg, South Africa, today (July 17) at 8:55 a.m. EDT, in honor of the 100th anniversary of freedom fighter Nelson Mandela’s birth (July 18). It comes as he travels Africa as part of the Obama Foundation‘s The Leaders: Africa program, which brings together "200 emerging leaders from across the continent to explore new ways to take on the biggest challenges in their communities."

Obama advisor Ben Rhodes told The Associated Press that the speech comes at an important time.

“At the current moment we’re in, values that we thought were well-established—the importance of human rights, respect for diversity—in many parts of the world those values are under threat,” he said. “Mandela’s life is an inspiring example of how we can overcome obstacles to promote inclusive democracy and an equitable society with tolerance of others.”

Watch the speech above.