Messi’s current deal is set to expire in June 2018 and Bartomeu has already said the Barca star has a contract forever at Camp Nou.
Manchester City have been linked with a move for Messi, but Bartomeu is confident of warding off interest from the Premier League.
“This is a decision for Leo Messi or for any player to change club,” Bartomeu told the Telegraph.
“Right now Leo Messi has a contract to the end of the Russian World Cup [in 2018] and we are very happy with him. Very happy. He’s the best player in the world, by far.
“I don’t know what will happen in the future but of course we will always try to explain to him that he is at the best club in the world and this is the best place for him to live and he is living the best experience of his life with us.
“He is still only 29. And if you see him playing it seems like he is one of our very young players. Leo Messi reinvented himself two years ago and changed the way he played and he is a better player now than he was then, a much better player. So normally players increase and then reduce but he is still growing. So where are the limits? We don’t know.
“We will have the negotiation with Messi in the next couple of months.”