Red Bull claim 2020 will be their "most expensive year in Formula 1" as they double up on development ahead of 2021.

Prior to the US Grand Prix, F1 bosses announced the new regulations that have been agreed, including an all-new car that is designed to promote closer racing.

Also included is a $175m budget cap with the aim of creating more competition, however, team boss Christian Horner believes its introduction is being undermined by the open-season that top teams will have next year.

"You have an unrestricted and uncontrolled amount of money that you can spend on research and development across other areas," he said in Austin.

"For me, I stand by what I said previously. It would have been better to have introduced the cap first and then the regulations a year down the line because then the budget cap would have constrained the amount of spend.

"Next year looks to be our most expensive ever year in F1."

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Indeed with a much better indication on how the new rules will look, Red Bull and others are wasting no time in getting to work.

"Now the 2021 regulations are clear, we have an advanced team starting to investigate those regulations," the Briton added.

"It makes it an incredibly expensive year because we are developing under two types of regs and before the new financial cap comes in as well.

"So 2020 will be an expensive and busy year, certainly off track and on track."

Countering the Red Bull chief's claim, however, is F1 motorsport director Ross Brawn who points to other restrictions that will limit just how far the teams can push on development.

“I think we should all remember that the most fundamental change with this car is in the area of aerodynamics, and that’s the area that’s most controlled, even within the existing regulations," he said via RaceFans.

“So I think that is an exaggeration, if I may say, of what’s going to happen next year with the new regulations and the effort the teams will put into it because they can’t.

"The 80-hour [limit] controls how much work they can do in the wind tunnel and therefore they won’t be able to exceed those limits and spend more time on this car. They’ll have to balance that between their existing car and the new car as they do every year.

“So I don’t see that next year is going to be that much different than the previous year.”

With CFD and other simulators becoming so much more advanced, however, what teams can do without needing the wind tunnel could be a key factor in whether Brawn or Horner is right.