Justin Timberlake at the Marine Corps Ball (Us Weekly)

The 'In Time' star was invited to attend the celebration in a YouTube video posted by Corporal Kelsey DeSantis and Justin has revealed the event – held at the Greater Richmond Convention Centre in Virginia – was deeply emotional for him.

In a blog post on his website JustinTimberlake.com, he wrote: "I knew I would have an evening that I wouldn't forget … Something I could tell my friends about. What I didn't know was how moved I would be by the whole experience.

"To all of you that serve every day for us … Ensuring our freedom, I say: My deepest gratitude to you. I've met so many of my heroes … From Michael Jordan to Michael Jackson. And, nothing makes me feel more honor and pride than when I get to meet one of you. Last night changed my life and I will never forget it. (sic)"

Justin – who recently reunited with girlfriend Jessica Biel - also reserved special praise for his 23-year-old date, describing her as a "hero".

He said: "She seemed to me to be so humble and honest … Very cool. She also simultaneously seemed like she was nervous about the whole evening and if I was going to enjoy myself. "Are you ok?" she asked 2 or 3 times. "I hope you are having fun. I know you will once my crew of friends get here to the table." I have to tell you, it's not every day that I meet a 23 year old girl and she's more worried about if I'm having fun or if I'm comfortable! It hit me all of a sudden that these were the type of people that look after us and our freedom … Humble, concerned for others before themselves … This was the type of person our Marine Corps was building. I was really blown away.

"Thank you Corporal Kelsey DeSantis. Thank you for inviting me. And, thank you for being my hero. (sic)"