Mohammed Ben Sulayem says Renault or any other engine supplier will not be able to stop Andretti-Cadillac from entering F1.
The FIA president is currently in a power struggle with Formula 1 commercial rights holder Liberty Media and the ten existing teams, who are opposed to Andretti being welcomed to the grid as early as 2025.
Months ago, Andretti actually agreed a provisional engine supply deal with Renault.
But Alpine team boss Bruno Famin now reveals that the agreement has expired and talks will not resume until the hopeful American concern is green-lit by Liberty.
According to FIA president Ben Sulayem, however, even the lack of a customer engine deal won't silence the Andretti bid.
"The rules state that no one can refuse them," he is quoted as saying in the latest edition of the Dutch magazine Formule 1.
"If all the suppliers say no, then the FIA has the power to appoint someone. These would be the suppliers that supply the fewest teams.
"We then randomly choose from those two and they then have to deliver," the FIA boss insists. "That's no secret either. It will probably be Alpine and Honda, and one of them will win because that's just the rules."
Although Andretti's bid is explicitly supported by General Motors-owned Cadillac, Ben Sulayem says the team would initially need to be powered by a customer engine.
But he says the goal is eventually for a works Cadillac engine.
"We also ask for that, and eventually that will happen," he confirmed. "But engines aren't made in just four or five years. So in the first years, Andretti will have to drive with another supplier."