President Obama on Tuesday shook hands with Cuban President Raul Castro, the first high-level interaction between leaders of the two nations in over a decade.

Obama briefly encountered the Cuban leader at the memorial service in Johannesburg, South Africa for Nelson Mandela, the anti-apartheid icon who died on Thursday at age 95.

It was unclear if the two leaders exchanged words. Both Obama and Castro shared the stage at the tribute, delivering speeches on Mandela’s legacy.

While lawmakers have visited Cuba in recent years and met with the top leadership in Havana, the handshake would be the first between the leaders of the two countries since former President Clinton shook hands with then-Cuban President Fidel Castro at the United Nations in 2000.

The U.S. has enforced a 50-year embargo on the communist country after Fidel Castro took power in the early 1960s.

President Obama has suggested that the U.S. needs a new approach to its Cuba policy and should consider broadening its links with the island nation.

“We have to be creative and we have to be thoughtful and we have to continue to update our policies,” said Obama during a fundraising event in Miami in 2012.

In his first term, Obama loosened travel restrictions on Cuba, making it easier for religious, cultural and academic groups to visit the island.

Any push to further thaw Cuba policy though will face criticism from GOP lawmakers who want the U.S. to maintain a hard line against Havana and who fear that travel and trade ties only strengthen the Castro regime.

The Obama, Castro handshake also comes on the heels of a historic breakthrough in U.S.-Iran negotiations, with those two countries negotiating a temporary deal that would freeze some sanctions in exchange for Tehran halting elements of its nuclear energy program.

That deal was made possible after Obama and Iranian President Hassan Rouhani spoke by phone earlier this year, the first high-level talks between leaders of those countries since the 1979 Iranian Revolution.