The Barcelona and Argentina great comes off contract at the end of this MLS season.
Mas, speaking with Futbol de Primera, declared: "My expectation is that we will see the team's captain and number 10, Lionel Messi, in the new stadium. It is a decision. We are talking to him about his future at the club.
"All the stars are aligned for really big things, a beautiful future for the club and for Lionel. It's up to him, but I expect we'll decide this in the next 60 or 90 days because it's important to start planning ahead."
Mas also emphasised that Messi's ties to Inter Miami will continue even after his playing career.
"He will become another member of the club, an acting shareholder, and he wants to leave it as a legacy to his children. We have a very nice, respectful relationship with him, and I let him live his things in peace," he added.