As Goal reported on Thursday, Barcelona communicated to the CBF that they would allow the forward to play in only one tournament - effectively ruling him out of the Copa America.
But while the CBF have confirmed the existence of the letter, they are not willing to admit defeat in the battle ahead of a crucial period for the national team.
A statement reads: "The Brazilian Football Confederation received on Friday afternoon (April 8) a letter signed by the Barcelona president Josep Maria Bartomeu, leaving clear the club's position over the participation of Neymar in the competitions the Brazilian national team will contest in the coming months: the Centenary Copa America and the Rio 2016 Olympic Games.
READ MORE | What we learned from the Champions League
"The club will only agree to free the player for one of the competitions."
It continues: "The CBF, by way of the National Team Committee, will make every possible attempt to have Neymar in the Centenary Copa America and Rio 2016 Olympic Games.
"Neymar has already publicly announced that he wishes to play both competitions for the Brazil national team and we will count on his efforts inside the club."