Spain will co-host the competition alongside Portugal and Morocco with three centenary matches played in Argentina, Paraguay and Uruguay.
The 2026 World Cup saw its biggest ever expansion after FIFA's controversial call to up the number of entrants to 48 national teams.
Rumours of 2030 stretching to 64 teams have been played down by FIFA, but CONMEBOL president Alejandro Dominguez has claimed the decision has already been made.
"In 2030, the World Cup comes to Uruguay, Argentina and Paraguay, a great opportunity for football, to celebrate the World Cup Centenary with a 64-team tournament."
FIFA have not responded to Dominguez's comments, but Gianni Infantino has confirmed there will be discussions over more expansions in the coming months.
"When you organise a World Cup, it's important to organise it for the whole world. It's not just Europe and South America, but the entire world. Every nation should be able to dream of taking part in the World Cup."