BARCELONA (REUTERS) - The head of Formula One's governing body has responded to criticism from drivers about rule changes by saying they had every opportunity to contribute but often failed to attend meetings.

International Automobile Federation (FIA) president Jean Todt also told reporters at the Spanish Grand Prix on Sunday (May 13) that he was always available to any driver who had an issue.

"I do respect them and know how busy they can be and all that. But they have access," said the Frenchman. "Unfortunately very often there is a meeting and they don't come to the meeting.

"I have always tried to hear what the drivers were saying. The drivers are invited to participate, to do something."

Todt pointed out also that he had appointed a number of former racers to FIA commissions.

Four-time world champions Lewis Hamilton and Sebastian Vettel had said on Saturday that new aerodynamic regulations for 2019 that would slow the cars by around 1.5 seconds a lap had come as a surprise.

Hamilton has also been critical of a draft layout for a potential Miami Grand Prix, saying drivers should have more of a say in circuit design and he could do better.

Todt said Miami was still very much in the realms of the hypothetical and that when it was firmed up, the FIA would send someone over to inspect and make recommendations.

"If the drivers have some comments they are more than welcome," added the former Ferrari boss.

"Any driver who wants to see me, from the back of the grid to the top of the grid, will be able to see me within 48 hours."

The 2019 changes are designed to allow cars to follow each other more easily by simplifying front and rear wings, opening up more overtaking opportunities.

Todt said that was also partly in response to driver complaints about how hard it was to overtake at some circuits.

"I read the press conference transcripts. Hamilton complained, Vettel complained, (Kimi) Raikkonen… they all complained. And they are in the front, so can you imagine at the back," he said.

"I read what you write. So I feel that if we understand that something is going wrong we should try to find a solution. We all say we want to have a better sport, a better show, so let's do something."

Some people, notably Red Bull principal Christian Horner, whose team enjoy the aero expertise of top designer Adrian Newey, have said the changes should have been left to a general revamp in 2021 when a new engine is also due.

Todt rejected that position.

"On one side people say let's wait to 2021. So it means we wait 2018, 2019, 2020 knowing that there is a problem that is damaging the sport," he said.

"We could say 'OK, there is not enough overtaking but leave it like that until 2021'. And then we say we want the fans to be happy. The fans want more overtaking."