President Donald Trump thanked North Korean dictator Kim Jong-un for returning some of the remains of American servicemen killed in the Korean War.

“The Remains of American Servicemen will soon be leaving North Korea and heading to the United States!” Trump wrote on Twitter. “After so many years, this will be a great moment for so many families. Thank you to Kim Jong Un.”

In a statement, the White House revealed that a U.S. Air Force C-17 plane had left North Korea with some of the remains on board. The remains will be taken to Osan Air Base in South Korea.

“Today, the Chairman is fulfilling part of the commitment he made to the President to return our fallen American service members,” wrote White House Press Secretary Sarah Sanders in a statement. “We are encouraged by North Korea’s actions and the momentum for positive change.”