Five-time Olympic swimming gold medalist Katie Ledecky said Wednesday she has been moved by the "positivity" of leukemia-battling swimmer Rikako Ikee and threw her support behind the young Japanese athlete's fight back to the top of the sport.

"She is a great swimmer and she is a great person," the American told Kyodo News in a video interview a day before Tokyo marks one year to go until the postponed Summer Games.

Ledecky said she came to know the 20-year-old Ikee through competing against her and is delighted to see the progress she has made on her path to recovery since revealing her diagnosis in February last year.