President Barack Obama shakes hands with Cuban President Raul Castro during the official memorial service for former South African President Nelson Mandela at FNB Stadium December 10, 2013 in Johannesburg, South Africa. (Photo by Chip Somodevilla/Getty Images)

At a memorial service for the late South African leader Nelson Mandela, a historic handshake occurred between Presidents Barack Obama and Raul Castro of Cuba.

Obama stopped to shake Castro’s hand as he made his way to the podium to speak on Mandela’s legacy. The president also shook the hand of Brazilian President Dilma Rousseff, who called off a trip to Washington earlier this year over allegations that her emails were intercepted by the NSA. Obama also briefly chatted with Afghan President Hamid Karzai. From the AP:

The U.S. and Cuba have recently taken small steps toward rapprochement, raising hopes the two nations could be on the verge of a breakthrough in relations. But skeptics caution that the two countries have shown signs of a thaw in the past, only to fall back into old recriminations.