Oct 21 (Reuters) - Formula One title rivals Lewis Hamilton and Max Verstappen have been close on track all season, at times too close, but otherwise they are keeping their distance. Mercedes" seven-times world champion Hamilton, six points behind Red Bull"s Verstappen after 16 of 22 races, had little to say when asked at the U.S. Grand Prix on Thursday how the relationship had changed as the title fight intensifies. "We have limited communication...some of the drivers hang more than others do. I wouldn"t say I particularly hang closely with anybody here," said the Briton, who has battled wheel-to-wheel and collided with the Dutchman. "Like last year, we will see each other at the track and we"ll say hi. We"ll do the same thing this year and it"s no different to me personally." Verstappen has won seven races to Hamilton"s five this year but Austin has been much more a Mercedes track than Red Bull in recent years. Hamilton has won five of the eight races held in Austin and Mercedes have been on pole for the last six at the Circuit of the Americas. This year could be a lot closer, however, and Hamilton -- winner of a record 100 career races -- recognised the next one in Mexico could also be tough. Asked how important it was to win in Austin, Hamilton said it was important to win every race. "It will be incredibly difficult. There will be moments where perhaps we can edge them out...I don"t like to assume that Mexico is not going to be strong but they are usually very strong in Mexico," said the Briton. "A lot can happen in these six races and so I think we just take it one race at a time and then give it everything we"ve got." Verstappen dismissed a suggestion he might be on a roll after seizing back the lead in Turkey two weeks ago, a race won comfortably enough by Hamilton"s Finnish team mate Valtteri Bottas. "We know that we still have a bit of work to do. We want to be faster," he said. "The team result was good in Turkey, the overall performance wasn"t amazing."