Ferrari Team Principal Frederic Vasseur has warned against "arrogance" in allowing Andretti Cadillac Racing to enter F1.
The American outfit has passed the initial two phases of the FIA's entry process, with four rival bids being denied progress after intense scrutiny by the governing body.
But Andretti must now close commercial discussions with Formula One Management [FOM] to ensure its position as the sport's 11th team.
The incumbent outfits have shown opposition throughout the process due to the threat an additional team can have on financial rewards each season, given the pie would be split between 11 teams rather than 10, all despite an anti-dilution fee being mandated as part of the Concorde Agreement.
The Andretti bid was initially an independent effort but, following cries of added value being necessary - likely backing from a manufacturer - the Indianapolis-based operation secured a partnership with General Motors and its Cadillac brand, which could lead to a power unit supply in the future.
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Giving his first thoughts since the FIA announced Andretti had been successful in the initial first two phases of its bid, Vasseur told media including RacingNews365.com: "It's not a secret that I am not a big fan.
"When we opened the door for an 11th team in the Concorde Agreement last time, it was for good reason.
"At that stage, Honda had said it would leave F1 and was on the edge, it meant we had only Mercedes and Ferrari confirmed for the future.
"We opened the door to an 11th team in the case it could bring something substantial to F1 - this stage this was mainly the engine.
"All the teams on the grid have made a big effort. We have to keep in mind that three or four years ago we had almost half the grid close to bankruptcy and we have to avoid arrogance that life is a cycle and we don't know what could happen before 2030.
"I think we would put F1 in a tough situation with this, except, as I said, if the new entry is bring massive value to F1.
"I don't have access to Andretti's dossier but I think that is the first question: 'What is the added value for F1?'
"We already have a team which is American with Haas, we have an American driver on the grid... the question for me is around this, what could be the added value?"