There are many things that need to be fixed in Argentine football. But I prefer to help from inside rather than stand on the outside and criticise," the statement continued.
"A lot of things ran through my head on the day of the [Copa America] final. And I seriously considered leaving the team. But I love my shirt and my country too much.
"I want to thank all the fans who wanted me to keep playing for Argentina. I hope we can give them joy very soon."
With the CONMEBOL deadline to name the squads for September's World Cup qualifiers looming on Friday, newly-appointed Argentina manager Edgardo Bauza had expressed confidence Messi would change his mind and opt to return to the team, and that belief was rewarded with Messi's confirmation later in the day.
Bauza, who took over as national team coach after the resignation of Gerardo Martino last month, had flown to Spain to meet Argentina players in Barcelona on Thursday and reassure them there would be order in the national team despite ongoing chaos in the football federation.