The postponement of the Tokyo 2020 Olympics was a heavy blow for many athletes, but a team of South Sudanese sprinters training in a Japanese town are hoping to turn the delay to their advantage.

The four athletes and a coach have been in the city of Maebashi, north of Tokyo, since November, taking advantage of training facilities that aren't available in their young but poor home country.

And with news of the historic postponement of the Games over the coronavirus, they've decided to stay on until at least July, hoping to beef up their skills.

"The Tokyo Olympics (have been) postponed. It's not a problem," team coach Joseph Rensio Tobia Omirok, 59, told AFP.

"I'm happy because I'm still training, and in other countries they have no training. They're sitting in their house but here we are OK... Training now is going OK."

The decision to postpone the Games for a year until July 2021 came after athletes and sports associations heaped pressure on organisers and Olympic officials, pointing to scrapped qualifying events and restrictions on training.

Japan has so far avoided the sort of major outbreak seen in Europe and the United States and even a state of emergency declared on Tuesday only applies to some parts of the country, not including Gunma prefecture, where Maebashi is located.

The city of 340 000 has pledged to continue helping the young athletes by providing them with accommodation, meals and the use of a local public track, along with an army of volunteer coaches and translators.

Maebashi decided to host the team - the coach, one female and two male Olympic sprinters and one male Paralympic sprinter - as part of its efforts to promote peace through sports. 

The athletes have visited local schools and community events to talk about their homeland, which won independence in 2011 and has been battling to recover from a civil war.

They regularly practise with local children and have learned to speak simple Japanese.

The athletes say they have come to enjoy life in the city, abloom with cherry blossoms after a bitter winter, despite being more than 10 000 kilometres from home, where they had to practise on simple empty fields, not a track.

"Before I reached Japan, I didn't know what kind of people the Japanese are," said Abraham Majok Matet Guem, 20, who runs the 1 500 metres.

"The love I got here... is more than even what I expected. So I have not missed home so much because I am staying in a very peaceful environment with very loving people. So I was very surprised at that."

The city has raised more than 14 million yen ($128 000) from across Japan through a special taxation scheme and is continuing to raise funds to secure the total 20 million yen needed to keep the team on through July.

Officials were quick to reassure the team they would be welcome to stay until at least July, after the Olympic delay was announced.

"We are eager to give them our continued support," said Shinichi Hagiwara, a sports official at the Maebashi city government.

The athletes' fate after that will be decided after the city consults with South Sudan's Olympic authority, the Japanese government, the track team and others, Hagiwara said.

The athletes said their warm reception left them hoping they might one day be able to welcome their hosts to their home country.

"Right now, people are scared to go to South Sudan. But we believe in the near future, it will be a very peaceful country and everyone will be free to travel there," said Guem.

"And we shall be happy to see people from Maebashi there also."

Guem left his mother and seven siblings at home to train in the city for the Games and said the delay was no more than a minor bump in his Olympic journey. 

"My dream is always, before I retire from athletics, I should become an Olympic medallist," he said.

"I will continue training and it is my hope to one day be a champion. I still have time."