Anna Baichibaeva, a sports programme director for the Games, told Russia's official state news agency TASS that the events would not take place sooner as work on the venues is taking place.

It is hoped the test events will take place in conditions which are as close to what they will be like at the Games as possible.

"Some of the venues we have now are only at the stage of examination, even those venues that already exist today will undergo a rather serious reconstruction," said Baichibaeva.

"It is pointless to carry out test events in them, venues will be in a completely different quality, in a different design, with a different set of premises. 

"All test events will take place between 2022 and 2023."

The Water Sports Palace for aquatics is among the venues being constructed for Yekaterinburg 2023.

Venues are also being built for volleyball, football, judo and sambo, as well as an Athletes' Village.

Last month, it was revealed that the total cost of construction work for Yekaterinburg 2023 will be more than 38 billion rubles (£380 million/$490 million/€417 million).

The Government of the Sverdlovsk Region is set to draft its regional budget for 2021 and pay 21.3 billion rubles (£209 million/$269 million/€231 million) towards the Games.

In August, it was announced that the total budget for Yekaterinburg 2023 had increased by more than six billion rubles (£61.2 million/$80.8 million/€67.8 million).

According to the Sverdlovsk authorities, the budget for the International University Sports Federation event stands at 64.721 billion rubles (£661 million/$866 million/€731 million) in total. 

Dates of between August 8 and 19 have been set for 2023.

Russia previously hosted the Games in Kazan in 2013.

Moscow also held the Games in 1973 when it was part of the Soviet Union, while Krasnoyarsk hosted the Winter World University Games in 2019.