UEFA is in talks with the South American Football Confederation over a joint Nations League that would see Brazil and Argentina feature in the expanded competition.
UEFA and CONMEBOL have fiercely opposed world soccer body FIFA's plans for a biennial World Cup, with the two this week signing an extended Memorandum of Understanding until June 2028.
European champions Italy are already also set to take on Copa America winners Argentina in the so-called 'Finalissima' on June 1 next year in London.
"UEFA is working on a number of projects with CONMEBOL, including a joint Nations League but nothing is finalised and no decisions have yet been made," a spokesperson said.
- Wembley on course to host Italy vs Argentina in June
- FIFA meets to discuss human rights in Qatar
- Infantino: Biennial World Cup opponents are scared
In an interview with Polish outlet Meczyki on Thursday, UEFA vice-president Zbigniew Boniek said the 10 South American teams will be added to the Nations League competition from 2024.
"From 2024 CONMEBOL will join the Nations League. We do not know yet in what formula, in what form," he said.
"We signed a memorandum about cooperation between CONMEBOL and UEFA and from 2024 these teams will play in the Nations League."
Boniek added that six CONMEBOL teams will join League A of the Nations League while the other four will join League B.
The entry of South American sides would increase the number of teams in the two groups from 16 to 22 and 20 respectively, with all the matches set to be played in Europe to avoid excessive travel.
The revamped Nations League would also represent direct competition to FIFA's plans for a World Cup every two years, a proposal Boniek said would be difficult to implement, adding that he was against the idea of introducing more new events.
FIFA will hold a global summit on Monday to discuss their ambitious plans, but UEFA president Aleksander Ceferin, who has been a vocal critic of the biennial World Cup idea, said the meeting would not be a defining moment in the process.
"As much as we know FIFA is still pursuing the project, there are some signals coming from different sides that they might not pursue it until the end," he said this week.
"We don't have a particular strategy. For Monday, it will be 211 federations, that means 500 people at the video conference. I don't expect something very deep."