Chase Carey insists that plans for a grand prix in Miami have not been scrapped.

In late September, the Miami city commission voted to indefinitely defer the plans.

Instead, F1 owner Liberty Media has announced a new grand prix in Vietnam for 2020.

That is despite Bernie Ecclestone telling Germany's RTL that, prior to him being ousted as F1 chief executive, he chose against the Vietnam plans.

"I did not want to have a grand prix in an area where we already have very good promoters," Ecclestone said.

Carey says he has not given up on Miami.

"The plan is to have a second race in the US," he is quoted by Speed Week. "But we are not just dealing with Miami, even if we are convinced that it would be a great project.

"The negotiations are going on. When it comes to street circuits there are many interests that need to come together and it takes time.

"But the (Miami) fan festival helped. Everyone thought the event was great. It was a positive step towards the race," Carey added.

At the same time, some more traditional races on the calendar - including Silverstone, Monza and Hockenheim - remain in doubt for the future.

"We want to keep the races with a long history," F1 commercial boss Sean Bratches is quoted by RTL. "They are important for the sport and for the fans.

"But in terms of race locations, nothing in this sport is unchanging. We are a business after all."

However, to get the preferred Miami project off the ground, Carey admitted that the way the promoter pays the annual fee could be tweaked.

"We will not turn the model upside down," he vowed. "But if the return justifies the risk, let's look at it."