Former Formula 1 supremo Bernie Ecclestone has said that the best thing about the sport's new era is that there is finally a fight at the front.

Invited as a guest of the respective promoters, despite only now having a hands-off role, the 86-year-old was present in both Bahrain and Russia recently.

He credits the success of the Sochi race to controversial Russian president Vladimir Putin.

"I remember when I first came here and I was discouraged," the Izestia news agency quotes Ecclestone as saying.

"I was not completely sure Russia would be able to build such a great track, but I relaxed after the guarantees given to me by Vladimir Putin. I know that your president only takes informed decisions.

"He will be remembered as a great president, who does a lot for his country and for world peace."

He said that he is sure Sochi will stay on the calendar beyond its 2025 contract, but confirmed reports that talks about a night race have now ended.

"We had the idea but I don't know if it's worth it. The TV pictures from Sochi in the afternoon are wonderful and everything is organised at a very high level, so there's no need to change," said Ecclestone.

Finally, Ecclestone spoke about the 2017 season, in which changes he presided over last year came into fruition in the form of the current, faster cars.

At the front, Mercedes finally has a challenger in Ferrari.

"I think Sebastian [Vettel] and Lewis [Hamilton] will continue to fight for first place," said Ecclestone. "It will be a very interesting fight.

"This year, Ferrari is really back in the fight for the top places, and that's very good news. Fans were very tired of Mercedes's domination of recent years, and increased competition helps the promoters to sell more tickets."

Just one point currently separates leaders Mercedes and second-placed Ferrari in the constructors' standings.