NAIROBI, May 18 (Xinhua) -- World 5,000m champion Hellen Obiri targets to move up to the marathon distance after the 2020 Tokyo Olympic Games.

Obiri, 29, however says she has unfinished business on the track and will push her luck to join the elite club of athletes who have doubled and won the gold at the world championships.

Speaking in Nairobi, Obiri hinted at doubling up in 5,000m and 10,000m at the world championships in Doha, Qatar later this year.

"I have not done the 10,000m on the track so I'm going to do it at the Kenyan trials (for the world championships). It's very hard to even make the Kenyan team but of course I want to make it and then from there you can see me doubling in Doha," said Obiri.

Obiri has had what she terms as 'amazing' start to the season. She raced to her first gold in World Cross Country in Aarhus, Denmark in March and when she launched her track season, she was in top form as she won in Doha Diamond League.

"Aarhus was the hardest cross country I have ever done and my international debut. Winning there was all I wanted," said Obiri, who took a break after the event in Denmark.

"Going into Doha, I thought I would do something like 8:30 but opening with 8:25 was amazing for me.

Obiri, who is also the Olympic silver medalist in 5,000m race, says she is keen to pick gold in Tokyo in 2020 in her specialty.

"I want to transit just like my friend Vivian Cheruiyot from track to marathon. My time on the track is almost over so it is important to start thinking of the road races," she added.

"I have never run 10,000m on the track so I wanted to do it before I go to the roads, maybe from next year after the Olympics. I will do 10km and the half-marathon from there and then maybe move up to the marathon."

In the meantime, Obiri heads to Manchester city in England for her second 10km road race after her debut in Madrid in January.

She will come up against compatriot and Boston Marathon runner-up Edna Kiplagat, world 1,500m record-holder Genzebe Dibaba and Tokyo marathon winner Ruti Aga at the Great Manchester Run on Sunday.

World cross country champion Jacob Kiplimo from Uganda and former New York Marathon winner Stanley Biwott from Kenya will headline the men's race.