Three venues were used this year - Madrid, which staged the semi-finals and final as well as group and quarter-final action, Innsbruck and Turin.

It was the second edition of the Davis Cup Finals since divisive changes were made to the format, scrapping the established practice of knockout ties being held in one of the two playing nations.

Centralised locations and groups were instead established, and they are set to be tweaked again in 2022.

The Davis Cup Finals will feature 16 teams next year - down from 18 in 2021 - and four groups of four, rather than six of three teams as was the case this year.

Each group will be played in a different city.

The top two teams in each group will then advance to the knockout stage, which is set for what the International Tennis Federation (ITF) called a "neutral fifth host city".

The venue for the last-eight competition has ben identified and will be announced this month, according to the ITF, while a bidding process for the groups will begin on December 15.

"The vision we set out in 2018 was to create a true world cup of tennis and we should be proud of what we have achieved together with the first two editions of the Davis Cup Finals," ITF President David Haggerty claimed.

"A five-city model will provide the flexibility of schedule needed, allow even more fans to enjoy the unique experience of Davis Cup and will secure the economic and commercial sustainability of the competition."

Haggerty, an IOC member, has said that the ITF will not move events from China because it does not "want to punish a billion people", so close attention will be paid to whether any Chinese cities are appointed to host.

The Women's Tennis Association, in contrast, has suspended all events in China over concern for the welfare of Peng Shuai, who was not seen for several weeks after accusing senior politician Zhang Gaoli of sexual assault.

Kosmos Tennis chief executive Enric Rojas added: "We are convinced that the format we are proposing for 2022 will make the competition even more visible and reach even more fans from all over the world."

The Russian Tennis Federation will be defending champions in 2022 and three other teams - Serbia, Britain and Croatia - are already assured places in the Davis Cup Finals.