Nico Rosberg says Lewis Hamilton's aggressive first-corner move at the U.S. Grand Prix was "one step too far" after his Mercedes team-mate secured a third world title in Austin.

Hamilton had a much better start off the line and went into Turn 1 alongside Rosberg and forced him wide and across the run-off area, dropping the German behind the two Red Bull drivers. In the end it had little bearing on a thrilling race which played out through changing conditions and was eventually decided by Rosberg's late error on the exit of Turn 12 which handed Hamilton the win he needed to wrap up the title.

However, after the race an angry Rosberg said his team-mate had crossed a line with the first-lap move.

"Turn 1 didn't have such a big impact on the race, what happened there, because I fought through well and came back to take the lead anyway," Rosberg said. "The main one is my mistake which lost me the race, but it always has some sort of impact, even Turn 1. I was ahead, mid-corner, I just looked at it. When I'm ahead I have the right to the track there and Lewis was too aggressive today. One step too far so that's not okay."

Rosberg was equally upset with himself after his late mistake handed the lead to Hamilton. The German driver nearly lost his car completely on the entry to Turn 13, allowing Hamilton by, and says he has never experienced anything like it before.

"It's really disappointing, a tough moment really and such a strange thing that's never happened to me before, never, not in practice, not in the whole season. To nearly spin off on my own like that nearly coming off a corner is just weird. I think the tyres were still a little bit cold, maybe, or something, I don't know. I don't understand it. That was really disappointing because the race was mine."

He also paid tribute to Hamilton's title win, admitting the English driver deserved it over the course of the year.

"Congratulations to Lewis, he deserves to win the championship. He's done a great season, he's driven well and consistent so its definitely well-deserved."