Undefeated light heavyweight champion Andre Ward announced his retirement from boxing Thursday at the age of 33.

Ward tweeted the following video as part of his announcement:

He also released a statement on his official website, saying he no longer had the desire to continue fighting:

"To the sport of boxing—I love you. You've been by my side since I was 10-years-old. You've taught me so much. You've humbled me. You've promoted me. I've sacrificed a lot for you, but you've given me more than I ever thought possible. You gave me a platform, made me a champion and helped me provide for my family. I am forever grateful to you. You and I will always be synonymous, connected at the hip. Thank you for all the wonderful people I've come in contact with because of you. I've made friends for life. As I walk away from the sport of boxing today, I leave at the top of your glorious mountain, which was always my vision and my dream. I did it. We did it.

"From the bottom of my heart, thank you to everyone who has played a part in my journey. You know who you are. I could not have done this without you. I want to be clear—I am leaving because my body can no longer put up with the rigors of the sport and therefore my desire to fight is no longer there. If I cannot give my family, my team, and the fans everything that I have, then I should no longer be fighting. Above all, I give God the Glory, for allowing me to do what I've done, for as long as I have."

The San Francisco native owns a career professional record of 32-0 with 16 wins by way of knockout.

His most recent bout was in June, as he defeated Sergey Kovalev by technical knockout in the eighth round to retain the WBA, IBF and WBO light heavyweight titles and win The Ring light heavyweight title.

Ward is also a former champion in the super middleweight division, and The Ring currently ranks him as the best pound-for-pound fighter in the world.

Golden State Warriors point guard Stephen Curry tweeted his support to Ward following the decision:

In 2011, Ward was named the fighter of the year by both The Ring and the Boxing Writers Association of America.

Prior to going pro, Ward won a gold medal for the United States in the light heavyweight division at the 2004 Summer Olympics in Athens.

Ward's contract with HBO expired in August, and he has done some work as a boxing analyst for Top Rank on ESPN since the Kovalev fight.