Renault and Red Bull look poised to extend their engine deal beyond 2016.
After the breakdown of their semi-works partnership last year, the parties agreed to enter a customer supply deal for 2016, with Red Bull's Renault engines now branded as Tag-Heuer.
"Everything Renault has promised has been delivered," Red Bull team boss Christian Horner said in Monaco, where Daniel Ricciardo is competing with his upgraded turbo V6 engine.
The two sides have already signalled their intention with the FIA to stick together in 2017, and negotiations are so well advanced that a deal could be struck this weekend.
However, it is believed that Red Bull is paying £21m to Renault this year, with the energy drink-owned team trying to talk down that price.
"Red Bull is as usual a tough negotiator, but it is the mutual desire to carry on as we are," said Renault's Cyril Abiteboul.
