Tuesday 10 January 2017 16:27, UK
FIFA's Council has unanimously approved Gianni Infantino's plan for a 48-team World Cup.
The council members chose Infantino's plan above four other options, one of which was to leave the tournament in its current 32-team format.
The new structure, featuring 16 groups of three followed by a 32-team knockout, is scheduled to be implemented in time for the 2026 finals and the allocation of the extra slots will be discussed "over the course of [the Council's] next meetings".
Infantino is already facing a revolt from Spain's La Liga over the plans but said after the vote: "We have to shape the World Cup of the 21st Century.
"Football is more than Europe and South America. Many more countries will have the chance to dream."
The Italian put World Cup expansion at the top of his agenda when he was installed as president Sepp Blatter's replacement last year, and a number of proposals were put forward.
Two involved 48-team finals, another two suggested expansion to 40 teams and the final option was to stick with 32 teams.
Critics of Infantino's preferred plan, which will see the number of matches rise from 64 to 80, included several high-profile clubs and the German Football Federation, which does not currently have a representative on the FIFA Council.
And the European Club Association reacted to the FIFA vote with a statement repeating its opposition.
It read: "We fail to see the merits to changing the current format of 32 that has proven to be the perfect formula from all perspectives.
"Questionable also is the urgency in reaching such an important decision, with nine years to go until it becomes applicable, without the proper involvement of stakeholders who will be impacted by this change.
"We understand that this decision has been taken based on political reasons rather than sporting ones and under considerable political pressure, something ECA believes is regrettable.
"ECA will analyse in detail the impact and the consequences of the new format and will address the matter at the next meeting of its Executive Board scheduled for the end of January."
But supporters including Jose Mourinho have pointed out the maximum number of games any team can play will remain the same at seven, while Infantino insists the format can fit into the current 32-day timeframe.
The next scheduled meeting of the FIFA Council is in Bahrain on 9 May.
