World record holder Eliud Kipchoge has backed Sir Mo Farah's decision to walk away from his marathon dream.

Four-time Olympic champion Farah announced his return to the track this month to take a shot at a third straight 10,000m gold at the Tokyo Games next year.

Farah won the Chicago Marathon last year but has never come close to repeating his track dominance during his two years on the road.

Olympic champion Kipchoge – who ran the first ever sub-two hour marathon in Vienna in October – will look to defend his London Marathon title in April and believes Farah could even return to the road.

He said: "Mo Farah didn't fail the marathon. He has already succeeded in the marathon. He has gone back to the track but after the Olympics I think he can come back in a big way.

"So he has already succeeded in the marathon and he knows how to handle the road. Next time, maybe next year, maybe in 2021 he can come back in a very big way.

"I respect Mo Farah as a sportsman and as a human being, I respect the conscience of Mo and his team. So if the decision is to go back to track then that is the best, you know. This is sport – you compete where your mind wants to go."

However, the 35-year-old refused to get drawn into a discussion over whether Farah was tainted by his links to former coach Alberto Salazar, who was banned for four years in October for doping violations.

He added: "I don't know, I don't want to comment on the Oregon Project. I am a Kenyan. I am training in Kenya, I think you will know more from those training in America."

Kipchoge has also been nominated for world sport star of the year at the BBC's Sports Personality of the Year award in Aberdeen on Sunday.

It comes as he targets a record fifth London Marathon win, having set the course record of two hours 37 minutes last year. And it is something he wants to break in 2020.

"I want to try to run a course record for London next year but it is still early to say anything, there are still a lot of months to come, four or five months," said Kipchoge, whose world record time from Berlin in 2018 stands at 2:01:39.

"I am training still at 10 or 20 per cent, so it is hard to say I will do this or this. But hopefully maybe by mid-March I will know what I will be doing in London."