Red Bull's team advisor Helmut Marko has revealed the team will continue to use the Honda manufacturer's power unit.
Honda announced last October that it will end its participation as an engine supplier at the end of the 2021 season.
Red Bull, who finished runners-up to champions Mercedes and have Dutch driver Max Verstappen and Mexican Sergio Perez this season, want to take over the intellectual property of the Honda engine rather than become a customer of another manufacturer.
Hamilton cheered at Mercedes HQ, Bottas gets open-top car farewell
"Everything has been settled between us. The timing is there," Marko, who is close to Red Bull's billionaire owner Dietrich Mateschitz, told German publication Auto Motor und Sport.
Max Verstappen (Red Bull) in Abu Dhabi
Image credit: Getty Images
"But there is only an OK when we have written proof from the (governing) FIA that the development stop on the engine side is coming.
"We are waiting for the FIA's decision," added the Austrian, who said the situation should be clarified by an e-vote of the FIA's F1 commission some time next week.
The current V6 turbo hybrid power units are due to be replaced in 2025 and the cost of continuing development would be beyond all but the major manufacturers.
The commission features teams, manufacturers, Formula One and the FIA with a majority required for the freeze to be approved.
Renault would otherwise be obliged to provide engines to Red Bull as the manufacturer supplying fewest teams at present. Mercedes have four teams using their power units and Ferrari three.
Honda are partners to both Red Bull and sister team AlphaTauri. Renault have only their own factory outfit.
'Best season ever' - Button and Rosberg on F1 title fight between Hamilton and Verstappen
‘It has been the weirdest season’ - Button feels Hamilton and Verstappen both deserved title