'We wholeheartedly support Simone’s decision and applaud her bravery in prioritising her well-being.'
Simone Biles pulled out of a second event at the Tokyo Olympics on Wednesday, withdrawing from the individual all-around competition to concentrate on her mental health.
Less than 24 hours after she had sent shockwaves around the world by dropping out of the team event, having completed just one vault, the American superstar said she would not take part in Thursday's final, USA Gymnastics said.
Jade Carey will take the 24-year-old's place in the all-around event.
"We wholeheartedly support Simone’s decision and applaud her bravery in prioritising her well-being," USA Gymnastics said.
"Her courage shows, yet again, why she is a role model for so many."
The governing body for the sport in the US said Biles would be evaluated to see if she can take part in individual apparatus competitions still to come.
On Tuesday Biles picked up her sixth Olympic medal for being part of the U.S. squad that went on to place second behind Russia.
International Olympic Committee spokesperson Mark Adams had said earlier on Wednesday the IOC has "huge respect and support" for Biles.
Adams said mental health remained a big issue and that it was a matter the organisation had been working on for some time.
IOC President Thomas Bach was seen in deep conversation with Biles on the floor of the Ariake Gymnastics Centre on Tuesday before handing out medals.
Biles was to appear in all six gymnastics event finals and a sweep of the gold medals would have given her 10, making her the most accomplished woman Olympian in any sport.
