"And as an American veteran, I am delighted to see that our former foe and we share some of the same feelings about this," Hudner said.
The monument to veterans is the centerpiece of a sprawling national military cemetery in Pyongyang's outskirts.
One North Korean, Pak Chun Son, sobbed as she paid her respects at the gravestone of her father, Pak Hyon Jong, who died in the war when she was 5.
"My father will be honored on this hill forever," said her brother, Pak Yun Yong, who was 8 when their father died. He was dressed in a military uniform weighed down by medals. Tears sprang to his eyes. "We want to raise our children to be patriots like their grandfather was."
Commemorations also are taking place in South Korea and the United States.
South Korean President Park Geun-hye attended a memorial event Tuesday in the southern city of Busan to pay her respects to the troops who defended South Korea during the war.
U.S. President Barack Obama is to give a speech Saturday at the Korean War Veterans Memorial in Washington.
AP reporter Eric Talmadge contributed to this report. Follow AP's Korea bureau chief at http://www.twitter.com/newsjean.