Tokyo 2020 Olympic medals are unveiled during the One Year to Go Olympic ceremony in Tokyo on Wednesday. AP

Tokyo Olympic organisers on Wednesday unveiled medals, which will be made from recycled materials collected from old electronics, as the city marked a year to go until the opening ceremony of the 2020 Summer Games.

The medals, designed to reflect the "energy" of athletes, are intended to "resemble rough stones that have been polished and which now shine," organisers said.

The gold, silver and bronze awards each have a rough, almost meringue like surface on the outer ring, encircling a smooth, shining centre.

"The medals collect and reflect myriad patterns of light, symbolising the energy of the athletes and those who support them," the organisers said.

The Tokyo 2020 Olympic medals are seen displayed for the media for a photo opportunity. Reuters

The medals were unveiled at a ceremony marking the year-to-go countdown until the Tokyo 2020 Games, with International Olympic Committee chief Thomas Bach praising the city's readiness.

"I can truly say I have never seen an Olympic city as prepared as Tokyo, with one year to go before the Olympic Games," Bach said.

"All the elements that make a truly outstanding Olympic Games are in place," he added, predicting "an amazing experience" for athletes.

The Olympic medals design was chosen from more than 400 entries from professional designers and design students.

"I never dreamed that the design I submitted only as a memorial to this lifetime event would be actually selected," designer Junichi Kawanishi said.

"I hope the medals will be seen as paying tribute to the athletes' efforts, reflecting their glory, and symbolising friendship."

Ryohei Miyata, who chaired the board that chose Kawanishi's design, said the medals showcased Japanese metal moulding techniques.

The medals will come on ribbons that use traditional Japanese chequered patterns and graphics that symbolises kimono layering techniques.

Miyata said there is "a beautiful balance between the design of the medals and their ribbons. It makes me want to strive for a medal myself."

The medals, which will weigh in at between 556 and 450 grams each, are being manufactured from metal extracted from mobile phones and other small electronics donated by the Japanese public as part of a campaign to make Tokyo 2020 eco-friendly.

Agence France-Presse