Under-pressure Biles eyes Olympic team gold in Tokyo

Simone Biles and her USA teammates will aim to retain their women's team title on Tuesday to take arguably the greatest gymnast in history a step closer to Olympic history.

Naomi Osaka is also in action as she pursues her challenge for a tennis gold medal for Japan, who top the medals table heading into the fourth day of the Tokyo Games.

Organisers are meanwhile nervously monitoring the progress of a tropical storm that is expected to make landfall in northeastern Japan during the day.

Rowing and archery events that could be affected by high winds have been rescheduled.

All eyes will be on Biles at the Ariake Gymnastics Centre as the 24-year-old four-time Olympic champion seeks to erase the memory of an uncharacteristically error-strewn qualifying competition.

Biles made mistakes on floor and vault on Sunday and the other Americans followed suit as they failed to post the top score of the day for the first time at a world championships or Olympics since 2010.

The US women came to Tokyo as odds-on favourites but Biles admitted to feeling the pressure in an Instagram post Monday, saying "I truly do feel like I have the weight of the world on my shoulders at times."

With spectators banned from the gymnastics and most events at the Games to protect the Japanese public from coronavirus, Biles does not have a crowd to inspire her.

Still, it would be a huge shock if she failed to win a fifth gold to kick off her attempt to equal or surpass Soviet great Larisa Latynina's record of nine gymnastics titles.

Osaka, one of the faces of the Games after lighting the cauldron at the opening ceremony, takes on 2019 French Open finalist Marketa Vondrousova of the Czech Republic in the third round.

With the competition between swimming superpowers the United States and Australia intensifying with each day, American great Katie Ledecky has to navigate a 200m semi-final in the morning before trying to recuperate for Wednesday's 1500m final.

Ledecky came up short in the first part of her eye-popping medal quest in Tokyo when Australian arch-rival Ariarne Titmus beat her to gold in the 400m on Monday. Ledecky is also swimming the 800m and possibly a relay.

The Russian team will be counting on world record holder Kliment Kolesnikov to bring home the men's 100m backstroke gold medal, one of four up for grabs in the morning session.

Organisers will hope the women's triathlon, which makes an early start on Tuesday, is not plagued by the same problems that beset the men's race 24 hours earlier.

In a farcical false start, around two-thirds of the 56 competitors dived into the water and set off only to be recalled.

The bungled start was caused by a media boat filming the competitors that had moved into their path. Once the race got under way, Norway's Kristian Blummenfelt prevailed.

Japan won three golds medals on Monday to move to eight overall, one ahead of the USA and two ahead of China.