The U.N. chief hailed the Korean War armistice as the “foundation” of peace on the Korean Peninsula on the 70th anniversary of its signing Thursday, while calling for a return to negotiations on North Korea’s denuclearization.

“We need a surge in diplomacy for peace,” Secretary-General Antonio Guterres said in a statement to mark the anniversary, calling the 1953 agreement the “legal foundation for the preservation of peace and stability on the Peninsula.”

Reflecting on the “bloodshed” before the armistice halted the war’s hostilities, he paid tribute to the victims of the war and those affected by the peninsula’s division.

“Today,