Red Bull team principal Christian Horner says the squad's partnership with Aston Martin should not be seen as the precursor to a Formula 1 engine deal.
Aston has been named as a Red Bull "innovation partner" in a deal linked to a hypercar project the two parties are collaborating on, with significant input from designer Adrian Newey.
Red Bull's current deal to run TAG Heuer-badged Renault engines, secured at the last-minute after 2015's ructions, runs only until the end of this season.
Speaking at the launch of the Aston Martin partnership in Melbourne, Horner said: "We are out of contract at the end of this year as you know and the choices in F1 are somewhere limited.
"Unfortunately Aston don't have an engine that we can use in F1. A V12 would be nice...
"Our engine discussions are separate to this, but obviously in an ideal situation we will find something that will work in harmony and unison."
Last year Red Bull pursued a Mercedes F1 engine deal that would have involved Aston badging, an arragement made possible by Mercedes parent company Daimler's five per cent stake in Aston.
Given the close relationship Red Bull has with Aston Martin CEO Andy Palmer and director of marketing and communications Simon Sproule, who were involved in the deal with former sponsor Infiniti, Horner suggested this partnership has the scope to evolve.
"Everything is possible," he said. "This is just the start.
"It is great for the Aston brand to be back in F1. To have it back with Red Bull is something that we are very proud of.
"With all these things it is the relationships that are important and we have enjoyed a great relationship [with Palmer and Sproule] over the last few years.
"There is the opportunity to come together and work together again and we jumped at it."
NEWEY WILL HAVE SPLIT ROLE
Newey stepped back from day-to-day involvement with Red Bull last year, performing more of a consulting role.
Despite Newey's commitments to the new hypercar, codenamed Project AM RB 001, his F1 role will remain similar this season.
"It will be a split role," he said. "We're in a position now where we have a really good depth of engineering inside the team.
"That means I can step back a bit and they know exactly what they are doing.
"We have some really strong heads of department and we can give them a bit more freedom."
Horner added: "Adrian has been splitting his time over the last 18 months between advanced technology projects and F1.
"Obviously that is working, the senior technical group have taken a big step forward over the last 12 months, and he will still be very much involved in F1."