WASHINGTON (AP) - President Donald Trump is bestowing the nation's highest military honor on a retired Marine sergeant major for valorous action in Vietnam 50 years ago.

John Canley's heroism includes twice scaling a hospital wall in view of the enemy to help wounded Marines and carry them to safety.

According to the White House, Canley fought off multiple enemy attacks over several days in early 1968 while his company moved toward Hue as part of a counter-offensive to retake the city from the North Vietnamese and Viet Cong forces.

Sgt. Maj. John Canley will become the 300th Marine to be awarded the Medal of Honor.

As a gunnery sergeant during the Vietnam War, Canley took command of 1st Battalion, 1st Marines, during the Battle of Hue City while saving lives and eliminating enemy threats over several days. pic.twitter.com/dKNrE0xLlr

— U.S. Marines (@USMC) September 25, 2018

Canley took over after his commanding officer was severely wounded, killing countless enemy fighters as his team retook Hue, in what was then South Vietnam.

Trump is presenting the Medal of Honor to the now 80-year-old Canley at the White House on Wednesday.