Dr Helmut Marko says it's "premature" to start celebrating Red Bull's works Formula 1 collaboration and 50 percent buyout by Porsche for 2026 and beyond.
Leaked company filings this week showed that Volkswagen-owned Porsche is buying half of the energy drink company's premier F1 team.
"I'm not allowed to accept congratulations yet," Red Bull's top Austrian official Marko told Kleine Zeitung newspaper. "These reports are premature."
In an official statement, however, Red Bull confirmed that "discussions" are underway with Porsche.
"We've had talks," Marko added, "but nothing has been decided yet.
"The VW Group has decided that it will go into Formula 1 if the new engine regulations will be enacted and contain several aspects. It's about the cost cap, newcomer status, CO2-free fuel and a few more points on top of that."
Fascinatingly, Marko hinted that the holdup in the FIA's finalisation of the all-new engine regulations for 2026 relates to Red Bull rivals Ferrari and Mercedes.
"We can't confirm anything at the moment," the 79-year-old former F1 driver said.
"Everything with the regulations has to be watertight as it will be an enormous change. There are also objections from Ferrari and Mercedes, who want to keep their advantage."
Also extremely likely for 2026 is the entry to Formula 1 of a second VW brand - Audi. The German carmaker is expected to buy into the Swiss F1 team Sauber.
Currently, Sauber competes in F1 as Alfa Romeo, but that deal would obviously end once car-making rival Audi is the works partner.
For 2023, though, Alfa Romeo CEO Jean-Philippe Imparato confirmed that the naming deal will continue at least for now.
"We have signed the renewal with Sauber for 2023," he told Radiocor de Il Sole 24 Ore.
"Every year we take stock in July to decide whether to continue this commitment. If one day we see that we no longer have interest or do not have a return on investment, we will evaluate.
"Everything will be done in an orderly manner but it is not a theme for this year."