The men's PT2 and the women's PT2 and PT5 were approved by the International Paralympic Committee Governing Board, which is meeting in the German capital Berlin.

PT2 includes athletes with comparable activity limitation and an impairment of, but not limited to, limb deficiency, hypertonia, ataxia and or athetosis, impaired muscle power or range of movement that have a classification assessment score of up to 454.9 points

PT5 is total or partial visual Impairment, including athletes who are totally blind.

They will join the men's PT1 and men's and women's PT4 classes announced in July, meaning there will be an equal split of events for men and women.

Wheelchair users are classified at PT1, while PT4 is for athletes with mobility impairments such as muscle power, limb deficiency, hypertonia, ataxia or athetosis that have a classification assessment score from 495 to 557 points.

A total of six gold medals will be awarded when triathlon makes its Paralympic debut at Rio 2016 ©Getty Images

Since July, the IPC and International Triathlon Union (ITU) have been working together to analyse all remaining sport classes and making the "difficult decision" of which should be the final three medal events.

Speaking on the day triathlon's place on the Tokyo 2020 Paralympic programme was confirmed, ITU President Marisol Casado, said: "We will remain committed to both campaigning for the inclusion of all remaining sport classes in Tokyo 2020, as well as to their continued development at ITU Para-triathlon events.

"ITU will continue to offer top quality competitive races in all of its sport classes, including world Championships every year, as well as development and classification opportunities.

"We are confident that if we all - Para-triathletes, NFs (National Federations), LOCs (Local Organising Committee) and ITU - continue developing during the next years, that all categories will be present at the Tokyo 2020 Paralympic Games."