Cyril Abiteboul has admitted that Renault needs a bigger budget in order to fight for the world championship.

The Frenchman said that when it comes to Renault's ambition of beating Mercedes, Ferrari and Red Bull, the team needs more money.

"True. It's something we need to work on," he told Globo.

"It's necessary to grow in all areas in terms of people, investment and, as you say, budget.

"So if we finish fourth instead of sixth, we will get more money and sponsors will be more attracted to our project. They will see that we have credibility. Success generates success in Formula 1," Abiteboul added.

"That is the cycle we need to enter and then we fight for the title."

Already pushing to fight for the title is Renault customer Red Bull, but that team is considering switching to Honda for 2019.

Abiteboul said that Red Bull is often too critical.

"Their comments are sometimes too harsh," he said.

"I admit that they are not unjustifiable, but it's not the best encouragement to provide the best we can for them.

"We work to the maximum to have a competitive power unit because we use it at our team as well."

Abiteboul also said that Red Bull could have accepted offers to better integrate its efforts with Renault.

"This complete integration of chassis and engine is required in F1," he said. "That's something we've never had with Red Bull. In my opinion, it was detrimental both to us and to Red Bull."

Abiteboul added that the F1 rules are partly to blame for Renault's struggle.

"The engineering challenge is immense, which is why Honda has difficulties," he said. "There are also those who interpret the regulations in a particular way to obtain extra power.

"The subject of burning oil is an example. We did not go down that path but it would have given us a lot more performance."

The championship continues tomorrow with the Canadian Grand Prix.