Chairman and CEO of Renault Carlos Ghosn says he doesn't expect the team to be competitive this season but has laid down the challenge to be victorious in F1.

At Renault's official Formula 1 team launch in Paris Ghosn has explained the reasons behind the French manufacturer returning as a fully-fledged squad, stepping up its efforts from an engine supplier after taking control of the Enstone-based squad Lotus over the winter.

Renault came under fire last season for an unreliable and uncompetitive power unit by Red Bull and Toro Rosso, with both teams opting to change engine set-ups for 2016. Toro Rosso has ditched Renault entirely and will use year-old Ferrari engines while Red Bull has taken engine development in-house with the support of TAG Heuer branding.

Ghosn expects Renault to continue to struggle against its Ferrari and Mercedes-powered rivals this season but says the company only decided to return to F1 if it could be successful.

"We are working a lot on the engine and are watching carefully the development of it," Ghosn said. "There are a lot of things planned for the season and the fact that we are starting with a handicap compared to the winners Mercedes. We think we have the talent, the willingness and the experience to close the gap. It may take some time but we are going to close the gap.

"We are not here to participate we are here to compete at the highest level and eventually win. I would like us to know that after each race stops Renault was a contender. That is not going to happen in 2016 unless we have a miracle, it is going to take more time, but we are counting on our team to use everything in our hands to have a very competitive package as soon as possible."

As well as seeing F1 as an ideal platform to target expanding markets to promote its production vehicles, Ghosn believes Renault as an engine supplier never received a fair amount of praise despite securing four drivers' and manufacturers' F1 world titles with Red Bull.

"We took so much time to know exactly what we were coming back into but also having the right conditions - sponsorship, technology, development and partnership - to compete against some tough teams," he said. "That is why we are saying it is going to take two to three years to make sure we will be back in a solid way on the podium. We know very well that if the team wins it is the car and if the team loses it is the engine.

"If you want to get the most out of Formula 1 you have to be a full team because as if you are only an engine provider you put in a lot of investment and rarely get the merit of your investment. That is also one of the reasons why we are coming back.."