McLaren's Lewis Hamilton has hailed the Circuit of the Americas in Austin, Texas as a "great track".
The 27-year-old finished fourth in the second practice session for the United States Grand Prix on Friday.
"It is a great track to drive but the whole track is very difficult," BBC Sport quotes him as saying.
"It's very tough to get all the sectors together. I find the second and last sector the easiest.
"The first sector is the hardest with the high speed; there are several different lines you can take and it is massively quick."
Hamilton is currently fifth in the drivers' championship.
