Watch Obama Greet Raul Castro In Historic Handshake At Nelson Mandela Memorial [VIDEO]

As President Barack Obama made his way to the podium at late South African leader Nelson Mandela's memorial service in Johannesburg on Tuesday, he stopped to greet other leaders in a line of dignitaries. One of the first in that line happened to be Cuban President Raúl Castro, with whom Obama shook hands and appeared to exchange a few brief words in what may have been a spontaneous encounter. The handshake marks the first between a sitting US president and Raúl Castro and only the third time one of the Castro brothers greeted a US president. Watch video of the encounter below.

In 2000, Raúl's brother Fidel shook hands with then-President Bill Clinton at a United Nations summit in New York. The Clinton administration went to considerable lengths then to downplay the significance of the encounter, the first between leaders of the two countries since the 1959 Cuban revolution. It initially denied that the handshake, had even taken place, then said that Castro had approached Clinton as the two made their way to lunch. Then-Secretary of State Madeleine Albright told reporters afterward that it was a "chance encounter" with "no substance", adding, "It was just a cordial conversation." NBC notes that the second encounter between a US president and a Castro brother occurred in 2002, when former president Jimmy Carter traveled to Cuba - the first by a sitting or former American president since 1959, when Castro took power - and met with Fidel.

Obama's encounter with Raúl, who took over the reins from longtime leader Fidel in 2008, came just before the president took the podium and eulogized the late Nelson Mandela as the "last great liberator of the 20th century." He also hugged Brazilian President Dilma Rousseff, with whom things have gotten testy after revelations of spying carried out Brazilian officials by the National Seecurity Agency, and the notorious Robert Mugabe of Zimbabwe. Under Obama, the US government has eased travel restrictions - rolling back several imposed by the Bush administration, such as one which limited the number of visits Cuban-Americans could make per year - but continued to denounce the island nation's human rights record. His administration has also negotiated over small apertures on issues like immigration, postal services and potential oil spills.

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