Max Verstappen has become "very mature".

That is the view of FIA race director Charlie Whiting.

Earlier in 2018, the Red Bull driver struggled with a series of mistakes. But after that, Verstappen's form surged.

"True, after Monaco, things changed. I would say that the last 12 races have flowed very well," he told Globo in Brazil.

"I wanted to get results too much and in the wrong way, with a lot of anxiety," Verstappen admits.

"I had to stop, work, reflect, slow down, which made me fast and consistent. Before it was all or nothing and I took enormous risks.

"I'm still aggressive, but in a way to keep everything under control," he added.

Whiting says he has noticed that change, even though Verstappen will still not hold back his strong opinions when he is penalised.

"Max has given the sport new dimensions, searching for and seeking out his limits. In the emotion of the moment I understand his reaction when he or someone else gets punished," he told De Limburger.

"But I recently spoke with him on the plane after his victory in Mexico, and he has become very mature," Whiting added.