Mario Andretti, America's last Formula 1 world champion, believes the revived United States Grand Prix will be a long-term success.
The 72-year-old, champion in 1978, says the new event in Austin, Texas, has the ingredients needed to become a fixture on the calendar.
"It needed something like this [circuit], to be an event you can look forward to every year," he said.
Andretti said the race would prove that there was a fanbase for F1 in the US.
Apart from a period through the 1970s and into the early 1980s, when there were successful grands prix at first Watkins Glen in New York State and then Long Beach in California, F1 has always struggled to gain a solid foothold in the USA.
A succession of temporary circuits in various cities through the 1980s early 1990s all failed and an eight year-spell on a track built within the famous Indianapolis oval ended in 2007.
But Andretti said the new event in Austin had attracted nationwide media interest, reflecting a substantial fanbase for F1 in the country.
Andretti, who describes himself as a "cheerleader" for the event, said: "I've done more interviews for this race than I can remember and that's a great thing.
"Let's face it, we're saying F1 needs America and America needs Formula 1. I think it's both. It's a win-win situation.
"The majority of the sponsors there are in F1 are global companies that do a lot of business in the United States, so to have the exposure in this big market here is what's needed. This is a good thing."
He added: "They probably don't realise that there is a fanbase. That has been understated grossly in my opinion and I think that's what we're going to find out.
"We can look forward to this next year and then the following year and the following year. There has to be stability and then you'll see the fanbase is for real."
Andretti believes that the changes to F1 in the last couple of years that have increased the amount of overtaking will make it more attractive for the American viewers.
He described the current season as "one of the best in memory", adding: "American fans like to see a lot of overtaking and now we've seen more action than we've seen in many years so it is catering to a lot of those wants and needs, so things are going in the right direction.
"F1 is truly enjoying great moments these days."
Andretti said a second race in the US, such as the one planned for New Jersey in 2014, would only help because the two events "could feed off each other".
But he admitted that scheduling the return of the US Grand Prix this year on the same weekend as the Nascar season - America's most popular motorsport - ends in Miami was not helpful.
"It would have been better if it wasn't - for both," Andretti said, "because you do have a crossover of fans. I know personally that some people that are down there would have been here and maybe even vice versa. Two very big events happening within not very much distance as well."
He also admitted that having an American driver in F1 "would be very helpful".
And he said he was sure the Circuit of the Americas had a business plan that would make it sustainable in the long term, despite F1's high race fees.
"They have a lot of events here, even outside the racing events, to keep this place available and busy year-round," Andretti said.
"The weather situation is very favourable. They are talking about concerts, they're talking about everything. They are going to build some hotels in the proximity so you can have conventions. It could be a very big attraction.