The FIFA Council has rubber-stamped plans to expand the World Cup in 2026 to 48 teams, adding 16 nations.
FIFA president Gianni Infantino's revamp plan received unanimous backing at a meeting in Zurich on Tuesday.
Delegates were asked to vote on four proposals to change the existing format or stick with the current format of 32 teams.
This is the first time since the 1998 World Cup that changes have been made to the makeup of the tournament, with the 2026 competition set to feature 16 groups of three.
The FIFA Council unanimously decided on a 48-team #WorldCup as of 2026:
16 groups of 3 teams. Details to follow after the meeting.
- FIFA Media (@fifamedia) January 10, 2017
Infantino's preferred option for change was for a 2026 competition featuring 16 groups of three, followed by a 32-team knockout, increasing the number of games from 64 to 80 but remaining inside a 32-day schedule.
"We have to shape the football World Cup of the 21st century," said Infantino, who also promised funding increases for FIFA's 211 member federations at his election last February.
"No guarantees have been made,'' Infantino said. "The only sure thing is that obviously with 48 teams everyone will have a bit more than they have today."
There were also options to have a 40-team tournament, with 10 groups of four or eight groups of five, but the only other 48-team makeup would see a 32-team one-game knockout round with the winners joining 16 already-qualified teams.
Infantino has also suggested that penalty shootouts be brought in to settle the results of all drawn games, thereby minimising the risk of teams colluding in their final group games to eliminate others from the tournament.
The Swiss has repeatedly said his main motivation for expansion is to give more nations a chance of experiencing the joy of a World Cup, which will bolster international football in developed markets and help its growth in new ones.
With 80 matches instead of 64, FIFA forecasts $1 billion extra income from broadcasting and sponsor deals, plus ticket sales, compared to the $5.5 billion forecast for the 2018 World Cup in Russia.
FIFA's six continents should find out by May how many extra places they will get.
The African and Asian nations are expecting significant increases on their current allocation of four spots apiece, while UEFA wants 16 European teams in the tournament.
The other major decision regarding 2026 -- who will host the event -- is not scheduled for consideration until 2020, with a bid featuring United States, either on its own or in conjunction with one or both of Canada and Mexico, the overwhelming favourite.
The European Club Association continued its stance of opposing the move, calling it "regrettable" and claiming it had been made because of "political reasons."
Information from The Associated Press was used in this report.