Franz Tost admits the engine situation for Red Bull's two Formula 1 teams is one "we would rather not be in".

Although Mercedes backs the energy drink company's plans to go it alone with Honda's IP and operations post-2021, the other manufacturers Ferrari and Renault are not prepared to agree to a development 'freeze'.

"We are currently living in a situation of uncertainty regarding the choice of engines in 2022," Tost, who is the boss of Red Bull's second team Alpha Tauri, told Italy's Autosprint.

"We could consider moving on to a competitor's power unit, but I prefer a further partnership with Honda," he added.

"They've done a great job in 2020 and their power unit has been really great this season," Austrian Tost added. "Now we'll have to see what happens next.

"That is obviously a position we would rather not be in. We have to be clear about the future already this year because the guys at the factory are already working on the design of the chassis for 2022," said Tost.

"It's important for them to know which power unit we are going to use, because it must of course fit in the car."