American gymnast and four-time Olympic gold medallist Simone Biles has withdrawn from Thursday's individual all-around final in Tokyo.

Biles, the most successful US gymnast of all time, said she had to focus on her mental health after pulling out of the women's team final on Tuesday.

The head of the US Olympic team and fellow athletes praised Biles' decision to prioritise her mental wellbeing.

The 24-year-old has reached all five individual finals in Tokyo.

She was due to defend her all-around title on Thursday before competing in the finals of the vault and uneven bars on Sunday, 1 August, floor on Monday, 2 August and beam on Tuesday, 3 August.

USA gymnastics said: "Simone will continue to be evaluated daily to determine whether or not to participate in next week's individual event finals.

"We wholeheartedly support Simone's decision and applaud her bravery in prioritising her wellbeing. Her courage shows, yet again, why she is a role model for so many."

Biles scored her lowest Olympic vault score in the opening rotation before withdrawing from the team final.

She left the arena but returned to support her team-mates as the defending champions claimed silver behind the Russian Olympic Committee.

Team silver in Tokyo was Biles' sixth Olympic medal and took her tally of Olympic and World Championship medals to 30.

Afterwards, Biles said: "After the performance I did, I just didn't want to go on. I have to focus on my mental health. I just think mental health is more prevalent in sports right now.

"We have to protect our minds and our bodies and not just go out and do what the world wants us to do.

"I don't trust myself as much anymore. Maybe it's getting older. There were a couple of days when everybody tweets you and you feel the weight of the world.

"We're not just athletes. We're people at the end of the day and sometimes you just have to step back."

Sarah Hirshland, chief executive of the US Olympic and Paralympic Committee, said Biles had "made us so proud," adding: "We applaud your decision to prioritise your mental wellness over all else and offer you the full support and resources of our Team USA community as you navigate the journey ahead."

Several athletes praised Biles, including Jamaican gymnast Danusia Francis who said: "Don't know about you but I think Simone Biles just empowered everyone to put their mental wellbeing above everything else. What a queen. GOAT in more ways than one."
'Biles returned and cheered her team-mates - that is a champion'

Speaking on BBC Olympics Breakfast about Simone Biles and mental health in sport, 2016 hockey gold medal winner Sam Quek said: "Watching it unfold yesterday I was getting more and more frustrated.

"I'd see headlines popping up saying she was weak, she wasn't mentally strong enough to deal with the pressure. On social media, people accused her of using it as an excuse to pull out because she wasn't performing as well. It's absolute nonsense.

"She said she wasn't in the right mental frame of mind to go and perform well enough and that she could have caused herself some damage. Every sports person knows that if you go in half-cocked, you're going to cause yourself an injury, none more so than in gymnastics.

"Even more importantly, she's laid a foundation for so many athletes and so many people around the world to say 'do you know what, the amount of pressure, the amount of eyes on me in this moment in time, something doesn't feel right'. That she had the bravery and the courage to pull out of the event is just huge.

"To the people accusing her of not being a team player and that she just wanted to focus on the individual - in my mind, she could not have been more of a team player.

"Simone could have hid in the background. She could have been in the changing rooms and left the world guessing about it, but she didn't. She put her tracksuit back on, got out there and stood on and clapped her team-mates. That, to me, is a champion."

Fellow former Olympic champion Chris Mears said: "I can relate to it. She feels like she has the weight of the world on her shoulders.

"She feels like she's failed and she probably feels very confused and doesn't know what's up or down. You have to applaud it.

"After winning gold in Rio, it was so amazing. It was like all your wildest dreams coming true. Then, for me, I came crashing down. I didn't know how to process. No-one teaches you how to process becoming an Olympic champion."