World footballing body FIFA voted on Tuesday to expand the number of national teams in its World Cup from 32 to 48.
The change will come in from 2026, FIFA confirmed.
Tuesday's unanimous decision will result in 16 groups of three teams each; these will then continue to a 32-team knockout stage.
Russia will host the 2018 World Cup and Qatar the 2022 finals.
The host country for the 2026 World Cup has not been determined.
FIFA's expanded format, the first increase in team numbers since 1998, is expected to increase revenues by $1billion.
