Lewis Hamilton struggled to comprehend his proximity to greatness after moving to within one of Michael Schumacher's tally of Formula One world championship titles.

Hamilton claimed his sixth global triumph with his second-place finish at Sunday's United States Grand Prix, the Mercedes driver taking an unassailable standings lead over team-mate and race winner Valtteri Bottas.

It marks Hamilton's third championship in succession and, at the age of 34, he is closing in on the legendary Schumacher, having moved one clear of Juan Manuel Fangio in the all-time list. 

However, an emotional Hamilton could not begin to contemplate joining or even surpassing the German at the summit.

"It was so far away. Now yet it seems so close, yet it is so far away that I still can't really comprehend," he said. 

"So the challenges that we'll face in these next coming months – next season, you look at the other teams that really have been putting some astonishing performances in in the second half of the season.

"It's going to take another load of incredible performances and work from myself and the other people around me and I really don't want to have to think about it right now."

There are still two races to go in 2019 and Hamilton would need to win both in order to beat his best return of 11 victories in one season.