Sebastian Vettel hopes to “shut up” any fat ladies singing for Lewis Hamilton clinching the 2017 Formula 1 world championship as he reaffirms Ferrari’s progress this season to keep his title focus up.

The four-time F1 world champion has seen a 14-point lead fall into a 59-point deficit since the summer break to leave his title ambitions in tatters after a disastrous run of form which includes two retirements in the past three races.

If Hamilton wins the United States Grand Prix this weekend and Vettel finishes sixth or lower the Mercedes driver will wrap up his fourth F1 crown with three races to spare but even if the German prevents that from happening the odds will be heavily stacked against him next weekend in Mexico due to the huge points deficit.

While Vettel accepts his “chances are a bit slimmer” for the 2017 F1 world title he isn’t thinking about giving up on the championship until mathematically certain and is simply targeting wins for the remainder of the year starting in Austin.

“In English, they say it’s not over until the fat lady sings. We need to make sure she shuts up for quite a while,” Vettel said “I’m not looking that far ahead, I never have to be honest, not looking behind, I’m really focusing on what is coming right now.

“We are still in there. Obviously are chances are a bit slimmer than they had been some races ago but still I think there is a chance so we are going for it and I think it would be completely wrong to drift off. I think we need to stay focused.

“We have a great car and the package to win the last couple of races. As it happened we didn’t but that doesn’t mean we have no chance to win the next race. We need to look forward to what is next and the next race is here.”

Despite a terrible trio of races in Asia, due to a first corner clash with Max Verstappen and Kimi Raikkonen in Singapore plus reliability woes in Malaysia and Japan, Vettel has defended Ferrari’s progress in 2017 as title contenders and its capabilities to take on Mercedes at almost every race this year.

“Overall I think it has been a very good season so far,” he said. “Obviously, you always judge depending on the past couple of races and they were not so good but overall we are the team that has made most progress and everyone expected Red Bull to be very strong this year. As a fact they were not, especially in the beginning.

“I think it was a given that Mercedes will be strong, they are, but nobody expected us to be as strong as we are.

“I think there are plenty of positives but it is also natural that you look at whatever you are facing up with. At the moment it might be a bit tricky but as I said we have races ahead of us and a strong car.”