Trump in a letter to Erdogan: 'Don't be a fool!'

U.S. President Donald Trump urged Turkish President Recep Tayyip Erdogan in a letter released by the White House Wednesday, to work out a deal with the U.S. over Turkey's invasion of Syria.

The president said the world will regard Erdogan forever "as the devil if good things don't happen." adding  "Don't be a tough guy. Don't be a fool!"  

The letter to the Turkish president was sent a few days after Trump had ordered U.S. troops out of northern Syria.