Ross Brawn believes Mercedes will continue to dominate next season and he feels the sport must look at how it can improve overtaking for the future. (1:38)

Lewis Hamilton says he has not considered the prospect of retiring from Formula One before the current engine regulation cycle expires in 2020.

Hamilton, who has won three of the last four championships with Mercedes, enters the final year of his current deal in 2018. The Englishman moved clear of Michael Schumacher's record for pole positions in 2017 but has said he has made it clear he has no ambition to actively chase or beat the German's tally of seven titles.

Despite that, he sees no reason to quit F1 while he is still enjoying his racing.

"I think about what is ahead of me," the four-time world champion said. "I have spoken to those who have retired early, those who retired late and everyone says stay in as long as you can. That's not going to happen.

"The seasons are getting longer and longer and you see the things I do outside, which take a lot of my energy and time. I'm enjoying what I'm doing now. I enjoy being with this team, I love racing and I still feel at the moment I'm driving at my best."

Lewis Hamilton is expected to extend his career with Mercedes beyond 2018. AFP PHOTO / CHRISTOPHE SIMON

"While the car is in this form of rules until 2021 at least, I think that's going to be the window I'm still here. Who knows? Maybe in 2021 I'll hand the baton over to [Mercedes junior] George [Russell]. He'll be there anyway before then. I'm going to keep going."

Both Mercedes drivers will be out of contract next season, with Valtteri Bottas handed a one-year extension earlier this year. Bottas' seat is likely to be the focus of more attention in next year's driver market speculation, with Daniel Ricciardo also entering the final year of his deal with Red Bull.