In 1987 Reagan made a speech at the wall.
He said

There is one sign the Soviets can make that would be unmistakable, that would advance dramatically the cause of freedom and peace.

General Secretary Gorbachev, if you seek peace, if you seek prosperity for the Soviet Union and Eastern Europe, if you seek liberalization: Come here to this gate.
Mr. Gorbachev, open this gate. Mr. Gorbachev, tear down this wall.
It is worth reading.
http://www.myfreedompost.com/2009/11/reagans-berlin-wall-speech-mr-gorbachev.html