Although long-term partners, the relationship has been fraught for years and Red Bull is now considering a switch to Honda power.
Renault has been pressing Red Bull to make a decision in May, but Red Bull says it wants to wait until the next grand prix in Canada.
“I believe Red Bull should behave responsibly,” team boss Cyril Abiteboul told France’s Auto Hebdo.
“They already have all the necessary data — I do not understand their evasive behaviour. They want to wait until Canada, but on Monday after the race in Montreal there will be no revelations.
“They are pleasing Honda and making Renault wait but we cannot wait indefinitely,” the Frenchman added.
In fact, Abiteboul said Renault is heading in its own direction anyway, and looking to promote only the interests of its own team rather than helping a rival to succeed.
“Everything else is an addition to our project,” he insisted.
“I would prefer to spend these three years while our team progresses with Red Bull Racing than without them, but one day we will have to break this connection,” said Abiteboul.
“It will be this year, next year or later, and while Red Bull can continue to help us, there will come a time when we need to be perceived separately,” he added.
“You could not imagine Mercedes or Ferrari supplying engines to Red Bull, so it’s necessary to get used to the idea that Renault will not either. We will say goodbye to these times when we are a supplier of engines,” Abiteboul added.