Jenson Button says Max Verstappen did "the most dangerous thing" a driver can do by moving under the braking zone during his battle with Kimi Raikkonen at the Hungarian Grand Prix.

Verstappen's robust defensive moves angered Raikkonen in Budapest, with the Finn later questioning why the Red Bull driver did not receive any penalties. Button sympathises with Raikkonen and says Verstappen should have known not to drive in that manner.

Speaking on Thursday in Hockenheim, Button said: "As drivers, we all know that moving in the braking zone is the most dangerous thing you can do because the guy [following] is at 300 km/h and probably hasn't hit the brakes yet. Moving under braking is a no-no and he obviously did move in the braking zone, so I can understand Kimi's frustration."

When it was put to him that Verstappen's move could be considered racing hard, he replied: "Moving in the braking zone's racing? Moving in the braking zone is not racing, it's dangerous.

"The whole time I've been in F1 you don't move in the braking zone, because that's where you have big accidents. It wasn't Esteban's fault in Melbourne but you look at the accident Fernando [Alonso] had, you happy seeing accidents like that? There you go.

Button was quick to point out his admiration for what Verstappen has achieved in his young career so far and said he may speak to the 18-year-old during the weekend, potentially at Friday's drivers' briefing.

He went on to say: "Max is an unbelievable talent in terms of what he's achieved at such a young age and he's doing a great job but there's obviously things we can learn as drivers. I think it just needs to be a bit clearer cut and as Kimi stated he thought it was dangerous."

Button's McLaren teammate Fernando Alonso agreed with the assessment that Verstappen was in the wrong.

"I think it was illegal, yes," the Spaniard said. "As I said, you are allowed to move once and commit to whatever you need to do. You can choose to brake on the clean side, the dirty side, on the inside, on the outside, you are allowed to do whatever you think is best to defend your position. But you are allowed to move once and not two or three times. That's enough. That is not an opinion, it's just the rule. If you take the ball with the hands outside the area it is a penalty and a red card, it's nothing more."