Messi, whose contract with Paris Saint-Germain expires June 30, revealed Wednesday that he would not return to Barca because he could not wait any longer to see whether they would be able to register his contract with LaLiga.
In a statement that drew criticism on social media, Barca responded by saying they "understood" Messi's decision to take himself out of the spotlight.
"On Monday, Jorge Messi, the player's father and representative, informed club president Joan Laporta of the player's decision to join Inter Miami," Barca said.
"This despite having been presented with a proposal from Barca, in consideration of the desire of both Barcelona and Messi for him to once again wear the club's colours.
"President Laporta understood and respected Messi's decision to want to compete in a league with fewer demands, further away from the spotlight and the pressure he has been subject to in recent years."
Barca are in excess of their LaLiga-imposed spending limit and can invest only 40% of any money they save or generate.
Even if Messi were willing to play for free, league sources said he would have accounted for €25 million within Barca's cap, based on previous earnings. Therefore, registering him is impossible. The scenario is remarkably similar to when Messi left the club in August 2021.
After revealing his intention to sign for Miami, Messi said he did not want to put himself in that situation again and wanted to keep his future in his "own hands."
Barca coach Xavi Hernandez, who led the charm offensive to persuade Messi to return to the club where he spent 20 years previously, said he respected the Argentina forward's decision.
"We speak a lot and I noticed a change in recent days," Xavi told Jijantes on Thursday. "[I felt] that maybe he didn't see [coming back] so clearly. We have to respect his decision.
"A lot of the time, we don't put ourselves in the shoes of others and we lack empathy. Being Leo, being Messi cannot be easy. You speak about the spotlight, imagine what it's been like for him. He has never had any quiet.
"When he's playing, he has to be the best, 10 out of 10 in everything, attacking, defending, he can't miss a penalty. He's not had a good two years [in Paris], he has explained that.
"The hope [he would come back] was generated because we speak a lot. We were all excited: him, me, the club ... but the circumstances didn't fall into place."
Messi, who turns 36 later this month, said the "final details" still need to be sorted before his move to Miami is officially complete, with his debut expected to take place in July once his PSG deal ends.
The seven-time Ballon d'Or winner could be joined at his new club by Barca midfielder Sergio Busquets, with sources confirming to ESPN that the former Spain midfielder is in talks with Inter Miami as well as two clubs in Saudi Arabia.
Xavi, meanwhile, said Barca's priority after missing out on Messi is to sign a creative midfielder and a replacement for Busquets, who is also out of contract on June 30.
However, he ruled out a move for PSG forward Neymar after rumours the Brazil forward has offered himself to the Catalan club.
"That's a surprise," Xavi said when asked about Neymar. "In theory, he's not part of our planning for the summer. I have a lot of time for him as a friend, but we have other priorities in the transfer market.
"The club know the players I want. I won't get into names, but we need a Busquets substitute and we lack another midfielder as well to play further forward."