"We are awarding an honour that is long overdue", Biden, 78, said at the ceremony. "I am incredibly proud to give Colonel Ralph Puckett's act of valour the recognition it has so richly deserved".
In November 1950, as a 24-year-old first lieutenant who had recently graduated from the West Point Military Academy, Puckett led a force that captured a strategic hill and held it against strong, numerically superior Chinese attacks during the Korean War.
"After 70 years I would have walked it to you", Biden told Puckett.
Visiting South Korean President Moon Jae-in attended the ceremony Friday before holding his first summit meeting with Biden.