Trump is expected to meet with Kim in late May or June.
He tweeted: “KOREAN WAR TO END! The United States, and all of its GREAT people, should be very proud of what is now taking place in Korea!”
In a separate tweet sent minutes earlier, Trump said “good things are happening, but only time will tell.”
Trump later offered credit to China, tweeting: “Please do not forget the great help that my good friend, President Xi of China, has given to the United States, particularly at the Border of North Korea. Without him it would have been a much longer, tougher, process!”