American gymnast and four-time Olympic gold medallist Simone Biles has withdrawn from Thursday's individual all-around final in Tokyo.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

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."