President Barack Obama has paid tribute to the fall 20 years ago of the Berlin Wall in a video message to the main anniversary event.
Obama said in the message introduced Monday by Secretary of State Hillary Rodham Clinton that the anniversary sends a message of hope to "those who believe, even in the face of cynicism and doubt and oppression, that walls can truly come down."
Obama said: "Let us never forget Nov. 9, 1989 nor the sacrifices that made it possible." He said the fall of the wall would always be remembered and cherished in the United States.
He said that "there could be no clearer rebuke of tyranny, there could be no stronger affirmation of freedom" than the sight of people tearing down the wall.
His message was greeted with applause and cheers.