Argentina, Paraguay and Uruguay have agreed on 12 cities where they want to host the centenary World Cup in 2030.
The Argentine Football Association said on Monday the plan would grant eight cities to Argentina and two each for Paraguay and Uruguay. The names of the cities were not disclosed.
Bidding is not due to open for another four years but leaders of all three national bodies say they want to make a joint bid.
The South American nations are expected to face tough competition for the hosting rights of a tournament that will likely feature 48 teams.
Uruguay staged the first World Cup in 1930 and has long been expected to seek hosting rights with Argentina. Paraguay later joined the initiative.
Argentine soccer officials said they met with national captain Lionel Messi during a recent trip to Spain.
"At all times we found (Messi) willing to help us spread the word about the possibility that the three countries organize the World Cup," Argentina's Sport Secretary Carlos Mac Allister said. "It's very important for us to feel that we have the support of players and that it is completely unattached from any political connotation."
Messi and Uruguayan striker Luis Suarez have already publicly backed the plan. During a recent Argentina-Spain friendly, Messi was expected to wear a bracelet that read "2030 together," but he was sidelined due to an injury. The bracelet was worn instead by Javier Mascherano.
So far, the co-organizers have not said how much the tournament would cost if they were to win the bid.
"Today, we can't say what the final costs will be to each of our countries, but it cannot be measured only in the building of infrastructure," Uruguay Sports Secretary Fernando Caceres said.
"There's an intangible measure, which is how much a country earns in coexistence, in integration, identity, and the construction of citizenship by hosting an event of this magnitude."