Argentina beat 2020 European Championship winners Italy 3-0 on Wednesday to lift their second title in the space of 11 months.
The Albiceleste upset Brazil 1-0 at the Maracana stadium last year in the Copa America final to win their first major title since 1993.
Photographs of Argentina's locker room celebrations after Wednesday's win went viral on social media and Neymar posted a comment under one Instagram post jokingly asking if Argentina had won the World Cup.
Neymar's comment emerged after Argentina international Nicolas Otamendi shared a clip of his team's locker room celebrations after Wednesday's triumph where players were heard singing a song dedicated to neighbours Brazil, reminding them of their Copa America final defeat.
"Brasilero, what happened? [Argentina captain Lionel] Messi went to Rio [de Janeiro] and got the Copa [America]," the song goes.
A big rivalry exists between the two South American countries.
Last year, Brazil players made fun of Argentina following their elimination from the football competition in the Olympic Games.
The Canarinha went on to win gold after beating Spain in the final.
Brazil and Argentina have gone unbeaten in qualifying to reach the World Cup in Qatar.