Barack Obama shook the hand of Cuban President Raul Castro on his way to speak at Nelson Mandela's memorial service.

The moment is special and unprecedented since the U.S. has held an economic embargo on Cuba since 1953, and Mandela was praised for his ability to unite enemies across political and racial divides.

Check it out:

During a powerful speech praising Mandela's life, Obama included a line that many thought was aimed at Castro, among others.

"There are too many leaders who claim solidarity with Madiba’s struggle for freedom, but do not tolerate dissent from their own people," Obama said.

Here's the GIF:

And here's another photo