Ferrari's Vettel: I had the speed to win 2018 F1 US GP in Austin

The Ferrari driver went into the Austin race with a three-place penalty for failing to slow sufficiently for a red flag during Friday's opening practice session, which left him fifth on the grid.

His hopes of a good result evaporated early-on when he tangled with Ricciardo, dropping him to 15th, but the nature of his recovery drive to fourth - and because team-mate Kimi Raikkonen went on to win - showed Vettel what had been possible without the issues.

When asked if he felt the win was lost in the Ricciardo clash, Vettel said: "I didn't try to lose the race in that corner.

"If we had stayed fourth or fifth after the first lap, then we would have been a lot closer.

"And then I don't know if everybody is doing the same things, but surely we had the speed to win."

Vettel's thoughts about having a car that could have come out on top were backed by Mercedes boss Toto Wolff, who was convinced that his team was simply not good enough in Austin.

"Imagine Sebastian not spinning out in lap one - I think he would have probably won the race easy," Wolff explained.

"It's stressful. With the drivers' championship, we are in a strong position but I always said we mustn't drop the ball. We've seen that in the past with other teams, and with the constructors' championship that is very important for the team.

"Nothing is done yet. There are 129 points to be scored - with the 66 points we have, of course that is also a good buffer. But there is no reason to giggle away and think you have the trophy in your hand, because we can see that we haven't got it in the hands."

Vettel felt the Ricciardo clash was a simple racing accident and that neither driver was to blame for what had happened.

"Obviously he tried to come back and we both just about managed to get the corner," he said.

"I think initially he had a bad exit out of [Turn] 12 but I came back.

"I had the inside but then I think he didn't see me, so we went side-by-side and then it was quite clear.

"He obviously tried to go around the outside and we touched pretty much wheels-on. So after the touch I lost the car and spun."