Girona and Barcelona, alongside La Liga, have formally made a request to the Spanish FA (RFEF) to play their January league fixture in Miami.
Last week, Girona confirmed they were open to the proposal because they see a "great opportunity for expansion" for the club and the city.
La Liga released a press release on Tuesday confirm Delfi Geli and Josep Maria Bartomeu, the presidents of both clubs, had jointly-signed the letter alongside league chief Javier Tebas.
The game is scheduled to be played on 26 January 2019 with a proposed 8.45pm CEST kickoff (7.45pm UK time) at the Miami Hard Rock Stadium, with the request submitted on Monday night.
Girona, who have only hosted Barca once at the Estadi Montilivi in a competitive match before but are said to be one of four top-flight clubs who support moving matches to the United States.
La Liga striking a 15-year deal with Relevent Sports to stage La Liga fixtures in the United States, a move which has caused huge controversy.
On Monday, league president Javier Tebas met with the David Aganzo, the president of the Spanish players union (AFE) after the latter’s threat of strike action.
Girona will reportedly receive €4.5m for the match while 1,500 fans will be given free air travel and accommodation by the league.