“We long for peace. However, if anyone threatens our people’s safety and lives, we will firmly respond,” he said, noting the two Koreas’ competition for dominance “ended a long time ago” with South Korea’s economy “more than 50 times” larger than the North’s.
Nearly 150 soldiers repatriated from Hawaii after being excavated in the North were formally received at the ceremony.
Video messages from the leaders of the 22 foreign nations that made up the UN coalition defending the South were played.
Earlier, Seoul and Washington’s defense ministers reaffirmed their commitment to defending “the hard-fought peace”.
Up to three million Koreans died in the conflict, the vast majority of them civilians.
Nearly 37,000 Americans were among the more than 40,000 UN soldiers killed, and Western estimates say China, which backed the North, saw 400,000 fatalities, while Chinese sources put it at about 180,000.