FIFA president Gianni Infantino has proposed staging what would effectively be a mini-World Cup, featuring eight international teams, every two years in addition to the traditional competition.

The tournament, known as the "Final 8", would be the climax of a global Nations League competition, which is part of an ambitious plan to reform international football which FIFA believes could be worth $25 billion in a 12-year cycle.

In a letter seen by Reuters, Infantino suggested that the new tournament would take place every October and/or November of every odd year starting from 2021.

He said that a "solid and serious" group of investors were willing to spend $25 billion on the competition and a revamped version of the Club World Cup, which would also start in 2021 with 24 teams.

The Confederations Cup, currently staged every four years in a year before the World Cup, would be abolished.

The letter did not clearly indicate how many slots would be allocated to each region.

The plans were sent by Infantino to the members of FIFA's decision-making Council which still has to approve them.

European football body UEFA and its counterpart for North and Central America and the Caribbean, CONCACAF, have already set up Nations League contests in their own continents.

In both cases, the competitions involve all the national teams in their respective regions who are divided into divisions based on their rankings.

There is promotion and relegation between the divisions, as in conventional domestic club leagues. UEFA's inaugural competition will begin in September this year.

Other continents would have to set up similar competitions for the tournament to be viable.