Tokyo 2020 revealed that hydrogen fuel will be used during the Torch Relay in three places - Fukushima, Tokyo and Aichi Prefecture - as reported by NHK.

Japanese refiner JXTG Nippon Oil & Energy Corp., an official Games sponsor, will provide the fuel, while there are also plans to use hydrogen generated in Namie in Fukushima Prefecture.

The Olympic and Paralympic cauldron, set to be placed in Tokyo's National Stadium, will be using hydrogen fuel, as will a second cauldron in the Tokyo Bay area. 

Tokyo 2020 claim the move is to promote clean energy and raise awareness of environmental issues. 

A similar initiative was in action at the Lausanne 2020 Winter Youth Olympic Games this month, with eco-friendly Swiss wood pellets used for the cauldron. 

Liquefied petroleum gas is normally used for Olympic Torches and cauldrons. 

The sustainability of sporting events is a much-discussed topic, with International Olympic Committee (IOC) President Thomas Bach referencing climate change as one of the areas the organisation's new Future Host City Commissions would consider when examining the potential impact on the Olympic Games.

The Tokyo 2020 Torch Relay is due to begin in Fukushima, struck by one of the worst natural disasters ever to hit Japan when an earthquake and tsunami triggered a nuclear disaster in 2011, on March 26. 

It will start at the J-Village Stadium, formerly used as an operational base for decommissioning work at the Fukushima Daiichi nuclear power plant.

Both Tokyo 2020 and the IOC are keen to use the Games to aid the region's recovery.

It is now six months to go until the Tokyo 2020 Olympics begin, with a fireworks display and the first lighting of the Olympic rings monument marking the occasion in the Japanese capital.