The USA's most decorated Olympic gymnast Shannon Miller wants Simone Biles to surpass her achievement at the upcoming Tokyo Olympics.

Miller has seven Olympic gold medals from the 1992 Barcelona Games and the 1996 Atlanta Olympics and Biles is hot on her heels.

At her first Olympics, 2016 in Rio, Biles picked up four golds and a bronze medal.

Miller told Reuters: “I’m excited about it. For me and for so many athletes, we feel that records are made to be broken. It’s how sport thrives, it’s how it evolves, and it’s how it progresses.

“It’s important for athletes to be inspired to do more and be more each and every year along the way. I’ll be among the fans cheering her on.”

Biles is already the most decorated world championship gymnast of all time as she collected her 19th gold at the championships last October. Miller has said she's amazed by the athlete.

"What strikes me is really the incredible amount of difficulty that she has in her skills combined with the consistency with which she competes those skills. That’s fairly rare.

“A lot of times you have difficult skills but you are not as consistent, or you’re very consistent but you don’t have as much difficulty. She has the combination of both.”