But Coe also took a sideswipe at "second-rate sociologists" who have questioned the scientific basis on which the rules were altered.

The 31-year-old South African last competed at the 2017 World Championships in London, where she won her third 800 metres title.

Since then she has switched to longer events due to the World Athletics ruling over naturally elevated testosterone levels and is now competing in the 5,000m.

Following scientific research athletes in this category are required to take testosterone-reducing drugs to compete in races from 400m to a mile or move to shorter or longer disciplines.

Semenya, who was 18 when she won her first world 800m title at Berlin in 2009, has made several unsuccessful legal attempts to overturn the ruling.

"She's eligible to be here," Coe said of Semenya, who missed qualification initially when she only finished sixth at the African Championships last month, but has benefited from a number of athletes dropping out and, world-ranked 81st, will run in the heats on the sixth day of competition in Eugene.

"If she chooses to compete in a distance that is not a restricted distance that's entirely up to her and she'll get the same treatment and same services as any athlete that's legitimately here."

Semenya is one of a handful of "restricted" athletes in Oregon, but Coe told AFP he didn't want "these athletes to go away any time soon".

"My whole approach to this has actually been about inclusivity," added Coe.

"I didn't come into the sport to stop people competing."

However Coe, who before Jake Wightman's victory was the last Briton to win a global 1500m gold when he retained his Olympic title at the 1984 Los Angeles Olympics, stressed that gender eligibility rules would not be changed any time soon.

"We've always been guided by the science and science is pretty clear: we know that testosterone is the key determinant in performance," he said.

"I'm really over having any more of these discussions with second-rate sociologists who sit there trying to tell me or the science community that there may be some issue.

"There isn't; testosterone is the key determinant in performance."

Coe said it was his responsibility to "protect the integrity of women's sport".

"We have two categories in our sport: one is age and one is gender," added the World Athletics President.

"Age because we think it's better that Olympic champions don't run against 14-year-olds in community sports and gender because if you don't have a gender separation, no woman would ever win another sporting event."

Coe said current restrictions on events from the 400m to the mile were "not set in tablets of stone".

"If we find there's an impact in other events, we will have to take that into consideration," he said, adding that it was "not about an individual, not about a country, not about a continent".

Coe added that we would not speculate on widening restrictions to events like the 200m, a distance that Namibian athlete Christine Mboma took silver in at the Tokyo 2020 Olympic Games, saying he would be "guided on science".

Semenya has a condition known as hyperandrogenism, which is characterised by higher than usual levels of testosterone, a hormone that increases muscle mass and strength and the body's ability to use oxygen.

She took medication after an initial ruling in 2011 by the IAAF - which became World Athletics in June 2019 - that all female athletes with hyperandrogenism had to lower their testosterone levels through medical means.

It made me sick, made me gain weight, panic attacks, I don't know if I was ever going to have a heart attack," Semenya said in an interview with HBO Sports in May.

"It's like stabbing yourself with a knife every day.

“But I had no choice.

"I'm 18, I want to run, I want to make it to Olympics, that's the only option for me."

In 2020 Semenya lost her appeal to the Swiss Federal Tribunal to set aside a 2019 Court of Arbitration ruling that female athletes with high natural testosterone levels must take medication to reduce it - something she now refuses to do.