"It is a year that I have missed things that matter a lot to me, such as Wimbledon, such as the Olympics, how the United States Open is going to be now, [and] many other events that are also important to me.
"During the past year I have not had the ability to train and prepare and compete in the way that I really like to. I came to the conclusion that what I need is time to recover."
Four-time US Open champion Nadal becomes the latest big name to pull out of the final major tournament of the year. Earlier this week, reigning champion Dominic Thiem withdrew through injury, and Roger Federer also confirmed last week that he would miss out because of a third surgery on his knee injury.
While Nadal's longtime rival said he had been left with only a "glimmer of hope" of a full recovery, the Spaniard was more optimistic.
"I am [determined] to do whatever it takes to regain the best possible shape, to continue competing for the things that really motivate me and the things that I have done during all these years," Nadal said.
"The injury is nothing new, it's the same injury I had in 2005. In that moment doctors were very negative about my future career, but I was able to have a career that I never dreamed about. So I am confident that I will recover again. The only thing you can be sure is that I am going to fight every single day to make that happen. I hope to see you soon."
His and Federer's absence opens the door for Novak Djokovic to overtake them both to become the most successful male player of the Open era. At Wimbledon in July, Djokovic equalled Federer and Nadal's record of 20 grand slam singles titles, and is the frontrunner to secure his 21st in New York in September.