'Mr. Kim, tear down this wall!'
On June 12, 1987, President Reagan stood before the Brandenburg Gate in Berlin and proclaimed, "Mr. Gorbachev, tear down this wall!" The people applauded.
Here is the bigger context:
Behind me stands a wall that encircles the free sectors of this city, part of a vast system of barriers that divides the entire continent of Europe. ... Standing before the Brandenburg Gate, every man is a German, separated from his fellow men. Every man is a Berliner, forced to look upon a scar. ... As long as this gate is closed, as long as this scar of a wall is permitted to stand, it is not the German question alone that remains open, but the question of freedom for all mankind. ...
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 not clear whether Mr. Trump will deliver a speech in front of the Korean DMZ. Perhaps he will be in meetings – or perhaps he won't meet Kim anywhere near the Korean peninsula. On the other hand, maybe Trump and Kim will also walk back and forth from one Korea to the other, as Kim and Pres. Moon did. In any event, his planners need to make room for a Reaganesque speech.
"Yes, Mr. Kim and Pres. Moon walked across the border. But more and lasting peace must be achieved. Mr. Kim, if your are serious, if you want to breathe the air of freedom – Mr. Kim, open the doors, permanently. Mr. Kim, tear down this wall! Keep it torn down to the end of time!"
Others can write a better speech than that, but the essence has to be the same.