The Camp Nou outfit have been credited with an interest in the 19-year-old sensation since the summer, along with arch rivals Real Madrid.
Neymar has always said that he will not leave Santos before the 2014 World Cup in Brazil and his new contract was made official on Friday.
"After 2014, when his contract expires, we will see," Rosell told COM Radio. "That is when he wants to take the next step.
"Neymar is a long-term affair. Then we will talk."
The Barca chief then stated he will not have the traditional lunch with Madrid president Florentino Perez on Wednesday, when the two clubs meet in the Copa del Rey.
"It would be too much, it is better this way," Rosell explained. "We will meet at the Bernabeu to have a glass of cava and wish each other a happy new year."
Starting in November and continuing through January, Goal.com is publishing exclusive extracts from Graham Hunter's highly-anticipated new book, 'Barca: The Making of the Greatest Team in the World'. The latest extract takes a closer look at the exciting emergence of Fifa Ballon d'Or winner Lionel Messi at Camp Nou: Don't miss it!