Top race executive Tom Garfinkel admits the otherwise popular and celebrity-fuelled inaugural Miami GP actually lost money.

In fact, he says the losses were greater than were actually anticipated, even though he doesn't regret spending big to put the new street event on the map.

"If you'd asked me six months ago, I would have expected the event to make money given how revenue has been going," Garfinkel, also boss of the Miami Dolphins and the Hard Rock Stadium, is quoted by Sky Deutschland.

"But if you look at expenses, we're not going to make any money this year."

He admits it's a blow, but insisted that by no means will it jeopardise Miami's new place on the Formula 1 calendar, which is guaranteed for a decade.

"It was very important to us to offer a great event," said Garfinkel, justifying wild expenses like the much-derided 'fake harbour'.

"The costs far exceeded our expectations," he admits, "but that was because we did everything we could to develop the Formula 1 brand and the type of event that we wanted to represent."

The event was actually a three-day sell-out, so for the future Garfinkel is looking to expand the maximum circuit capacity of 87,500 to at least 100,000 if possible.

He is also tackling the post-race hangover of multiple drivers blasting the quality of the circuit layout and especially the tarmac surface, which Lando Norris calls "crap".

"There are a lot of things we can learn from and do better," Garfinkel acknowledged.

"But there are also some things that went really well. The feedback has been very positive from the teams, the drivers, Formula 1 and the FIA."