Trump is responding to the meeting of North Korea's Kim Jong Un with South Korean President Moon Jae-in in South Korea. They pledged in a joint statement to rid their peninsula of nuclear weapons — but didn't identify any specific new measures to achieve that.
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."