The Argentina international, who has spent his entire career in Catalonia, is rumoured to be stalling on extending his contract beyond 2021.
Messi is allegedly irked at a number of off-field issues over the past 12 months, many linked to president Bartomeu's conduct.
However, Bartomeu is confident that the 33-year-old - who brought up his 700th goal for club and country last week - will remain at Barca for many more years to come.
"I'm not going to give details of the negotiations, but he has said many times that he wants to finish his career at Barca," he told Movistar+.
"Right now, we are focused on the competition and there are negotiations with lots of players.
"Messi wants to continue at Barca and he wants to end [his career] here. He has many years left and we're going to enjoy him for a long time."