Sources told ESPN earlier this week that United had agreed an initial €65 million fee with Barca for the Dutch midfielder, though it was said that there were still "significant" hurdles to overcome.
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De Jong, 25, is United manager Erik ten Hag's top summer target but he is also a target of other clubs.
"Frenkie de Jong is a Barca player and he is considered as one of the best players in the world," Laporta told reporters on Saturday. "We know other clubs wants him, not just [Manchester] United and we have no intention to sell him. I have a feeling that the player wants to stay.
"He is happy at Barca and I'm going to do everything I can for Frenkie to remain."
De Jong is under contract with Barca until June 2026 and has said publicly that he would like to stay at the Camp Nou.
Barca paid €75m for De Jong when they signed him from Ajax in 2019 with another €11m in potential add-ons.
Barca sold 10% of their domestic television rights to Sixth Street last week for €207.5m and sources told ESPN on Friday that they are hopeful of selling another 15% of their rights in order to further ease their perilous financial situation and raise up to €200m for transfers.
Barca's gross debt still stands at around €1 billion and they are operating within a LaLiga salary limit of -€144m, which is the only negative cap in the league. The limits will be updated later this summer.
Barca face stern competition to sign Brazilian winger Raphinha from Leeds United this summer. Sources told ESPN Chelsea have agreed a fee in excess of £60m for the Brazilian winger, while Tottenham are also monitoring the situation.
"We have spoken to Leeds," Laporta said of Raphinha. "We know he is a player that would like to come to Barca but there are also other clubs interested." Laporta clarified that Raphinha's potential arrival to the Camp Nou would not stop Barca from attempting to keep Ousmane Dembele at the club.
"It wouldn't exclude Dembele because the coach [Xavi] sees them as compatible," he said.
Dembele's contract at Barca expired last month and he is a free agent.
Barca coach Xavi is a big fan of Dembele, who scored two goals and set up 13 more in 32 appearances across all competitions this past season.
Laporta has not ruled out the French forward signing a new deal with Barca despite the player having so far rejected all contract extension offers.
"He [Dembele] is a person that we appreciate a lot," Laporta said. "He has played at a very high level in the second half of the season and the coach is really satisfied with him. It's a financial issue, he hasn't said yes or no to us. We have a good rapport with him and there is communication with his agents. If he accepts the conditions, we have presented to him, he will continue, if not, he won't.
"We don't have a deadline at all, not even for signings."
"We know that he has publicly declared he wants to come to Barca and we are flattered but we have a lot of respect for Bayern Munich, one of the best clubs in the world," Laporta added Saturday.
Information from ESPN's Sam Marsden and Moises Llorens was used in this report.