"We have got 21 races now. It could go more, but I don't think it will. It's enough. Some of the guys at the teams are shattered," said Ecclestone.
In a wide-ranging interview, Ecclestone also revealed that a sale price between two unnamed would-be investors and CVC, the owners of F1, has been agreed.
Formula 1's last attempt at a grand prix in Las Vegas was a failure. Named the Caesars Palace Grand Prix, it was part of the F1 world championship in 1981 and '82.
Australian Alan Jones was the inaugural winner, but the real story was the desert heat making the conditions for drivers atrocious.
Described as one of the worst circuits F1 has ever visited, the temporary track was set up in the Caesars Palace parking lot and had a counter-clockwise direction that also took its toll on drivers' necks.
The event ended after two seasons after it saw poor crowds and big losses for Caesars Palace.
Ecclestone's revelation came after unhappy drivers labelled the series' decision-making "obsolete and ill-structured" and called for a "restructuring" of its governance.
A rushed decision to change the rules of qualifying, and then subsequently scrap those changes after the season-opening Australian Grand Prix, showed how much F1 is riddled with confusion and uncertainty as it tries to regain popularity.
That was further underlined in another volte-face last Thursday when Ecclestone said the unpopular new qualifying format will remain in place - temporarily - at this week's Bahrain GP.
This comes after four-time champion Sebastian Vettel - a critic of the new qualifying format that underwhelmed spectators and frustrated drivers in Melbourne - joined former champ Jenson Button in demanding better leadership.
Both signed an open letter on behalf of the Grand Prix Drivers' Association (GPDA), along with its chairman Alex Wurz, to express their discontent.
- news.com.au