Lewis Hamilton admits he took caution attacking Max Verstappen in the closing stages of the United States Grand Prix with one eye on the Formula 1 world title picture.

The Mercedes driver missed out on his first opportunity to seal a historic fifth F1 world title at the first attempt with third place in a frantic US race, but still extends his championship lead to 70 points over Sebastian Vettel with a maximum of 75 points left to score.

While Hamilton was disappointed with Mercedes’ car performance and strategy calls, he concedes he opted to be ‘very, very careful’ fighting to overtake Verstappen for second place with three laps to go – which at the time would have handed the British driver the title.

“I was trying to win a race but you are looking at two guys next to me who are not fighting for a championship so I had to be very, very careful how it competed around them,” Hamilton said. “Championships are not won by fighting and making silly mistakes. I gave Max way too much space, just to be sure that I didn’t get caught for example or taken out if he had understeer or was aggressive.

“If that was me and Seb I would have been a lot more tighter and more aggressive if we were fighting for the championship but there was no need to be. The key was for me to finish ahead of Seb and for me it doesn’t matter when you win the championship as long as you get it done. Ultimately you always want to win the race and today going back two steps is not a good result as the car wasn’t perfect.”

Hamilton’s battle for a fifth consecutive United States GP victory swung on Mercedes’ call to “do the opposite of Raikkonen” during the early Virtual Safety Car period triggered by Daniel Ricciardo's mechanical breakdown on track. On Lap 11 Hamilton pitted, with Raikkonen staying out, which duly handed him the lead once Raikkonen made his sole pit stop later in the race.

But needing to stop for a second time, the strategy call backfired as he could only reach third place.

“My strategy was the same, I wanted to win the race as we were on pole position,” he said. “Coming down to the strategy we talked about different scenarios as we do every weekend. There is a feeling with the performance and the decisions were taken today as opposed to previous races but I didn’t think we needed to make many changes.

“I don’t know why they wouldn’t want to win the race I think they did want to win the race but it just didn’t play out the way that we planned.”

Hamilton feels the Mercedes strategy had a key flaw from qualifying when it opted to progress through Q2 on the middle compound, supersofts, while Ferrari’s Raikkonen would start on the ultrasoft.

The British driver feels the softer tyres provided the Finn with the vital performance edge to dart ahead in the first corner, in a similar style to the Austrian GP, which pushed Mercedes on the backfoot.

“It started from Q2, the tyre was the wrong tyre to start on and we’d already seen a long time ago this year that Kimi starting on the softer tyre, I think it was in Austria, and there was a big difference on the start performance between the different tyres yet we went the same way as before and lost a position,” he said.

“Then I wasn’t able to keep up as he had clean air and a better tyre. It was definitely an issue for us and we’ll look through it as performance-wise it wasn’t a great weekend.”