Obama shakes hands with Cuba's Raul Castro

David Jackson | USA TODAY

Show Caption Hide Caption Obama shakes hands with Cuba's Raul Castro Nelson Mandela's memorial service Tuesday brought together -- briefly -- the leaders of two long-estranged countries: The United States and Cuba.

Nelson Mandela's memorial service Tuesday brought together — briefly — the leaders of two long-estranged countries: the United States and Cuba.

President Obama shook hands with Cuban President Raúl Castro during the service at which both spoke.

The United States and Cuba have not had diplomatic relations since the communist revolution led by Castro's brother Fidel more than 50 years ago.

This appears to have been only the second U.S.-Cuban leader handshake in the last five decades. Back in 2000, Fidel Castro shook the hand of then-President Bill Clinton.

The Castro handshake was not planned, said Ben Rhodes, Obama's deputy national security adviser for strategic communications. The president greeted many of the world leaders who gathered for the Mandela service.

Obama only "exchanged greetings" with Castro and the other leaders, Rhodes said, adding that "what the day was about was Nelson Mandela."

Fidel Castro backed Mandela's anti-apartheid efforts, and Mandela often expressed his admiration of Castro. Fidel Castro visited South Africa for a conference in 1998, years after Mandela's release from prison and election as president.

During Mandela's memorial service in Johannesburg, South Africa,, Obama could be seen chatting with a variety of world leaders, including Afghanistan President Hamid Karzai.

"Mandela showed us the power of action," Obama said in his remarks at the stadium, "of taking risks on behalf of our ideals."

In his speech, Raúl Castro called Mandela "the ultimate symbol of dignity and unwavering dedication to the revolutionary struggle, to freedom and justice, a prophet of unity, peace and reconciliation."

At a 2009 conference, Obama shook hands with another prominent anti-American critic, then-Venezuelan leader Hugo Chávez.

From the Associated Press:

"Obama was greeting a line of world leaders and heads of state attending the memorial in Johannesburg. He also shook hands with Brazilian President Dilma Rousseff, who has clashed with Obama over alleged National Security Agency spying.

"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."