Lewis Hamilton is 100 per cent fit for the United States Grand Prix after sitting out a tyre test in Barcelona with a foot injury.

The reigning Formula One world champion was set to trial the Pirelli tyres that will be in operation from 2017 following the previous race in Suzuka, but pulled out with the problem.

Hamilton allayed any fears over his condition for this weekend, revealing it is an issue he had been struggling with all season.

"I am 100 per cent, I feel great. I basically had an injury that I carried all year long," said the Mercedes driver.

"Fortunately the physio said it just takes a lot of stretching over time. The most important thing was to be fresh for here, and this is the first week where it felt good."

Having triumphed in three of the four races since Austin was introduced to the calendar in addition to the 2007 race in Indianapolis, Hamilton is hoping for more success.  

He said: "Austin, America, has always been a good hunting ground for me. It is a fantastic track. They did a very good job with the design and it is one of the few newer circuits that allows following of cars and overtaking.

"The weather is going to be better this weekend [than last year], which is great for the fans and I am excited.

"No one's perfect, but all I can do is work hard with the team and there's no reason why I can't have more positive weekends moving forwards.

"I've been out here for a week already so I'm looking forward to fighting again."