The ceremony combined remembrance with reminders of what New Zealand Prime Minister Helen Clark called the "very critical challenge" posed by communist North Korea's nuclear weapons aims.
At 10 am on July 27, 1953, North Korea and the UN force signed an Armistice Agreement. It took effect 12 hours later and remains in force, meaning the Koreas are still technically at war - the heavily fortified DMZ is a vivid symbol of that.
"We pray that true peace may come to this Korean peninsula, and that this divided country may restore its 5,000 years of history and become one again," retired missionary Horace G. Underwood, 85, who interpreted at the truce talks, told the 1,500 veterans and 200 dignitaries at Panmunjom truce village at the heart of the DMZ.
"The armistice represents nothing short of victory, nothing short of an historic international stand against communist aggression."
-US Army General Leon LaPorte
Army General Leon LaPorte, commander of the 37,000 U.S. troops in South Korea, described the event in an upbeat rather than solemn speech as a "grand celebration" of the U.N. forces saving Chinese-backed North Korea from engulfing the South.
"To some, the armistice represents an anti-climactic finish to a complex conflict," he told the crowd in a tent that shielded them from rain. "(But) the armistice represents nothing short of victory, nothing short of an historic international stand against communist aggression."
North Korea, which says it won the war, has described the ceremony as a disgusting farce. A lone North Korean guard stood stone-faced on the far side of the dividing line.
Moves to curb North's nuclear ambitions
North Korea is edging toward talks with the United States and other powers in a crisis that erupted last October when Washington said Pyongyang had said it had a covert atomic programme.
At the ceremony, UN forces unveiled a stone arrow curving toward the off-limits hut where US Lieutenant-General William Harrison and North Korean General Nam Il signed the truce.
South Korean President Roh Moo-hyun used a speech at a separate South Korean memorial ceremony to call on North Korea to "abandon its nuclear ambition and to opt for the path toward peace and coexistence".