Mercedes dominated the first session with Valtteri Bottas on top ahead of Hamilton, while Max Verstappen trailed by over 0.9s in third.

The second session didn’t go as smoothly for the reigning world champions, ending it in third and fourth.

Reflecting on Friday at the Circuit of the Americas, Hamilton said: “Generally, it's been a good day but still work to do unfortunately. Not unfortunately, it's the way it is.

“P1 was really good session, made some changes and wasn't happy in P2. And still not such bad pace, but I think we lost some ground to a one or they gained ground. So we have some work to do tonight. As always.”

The seven-time champion admitted that finding the right car setup has proved to be most difficult so far and finding the balance between qualifying and the race.

“Definitely it's difficult because you're actually trying to get a qualy setup, and also a setup that will work on the long run, and it's easy,” Hamilton added. “It's not an easy track to set up in general, but I think there was plenty of findings from today, we should be able to navigate well.”

Bottas will be forced to start the race five places lower than where he qualifies on Saturday after taking another new ICE power unit component.

With another penalty looming over the Finn, he confirmed that he was focusing on race performance in second practice.

“Yes, again, unfortunately, I’ll have to take a penalty but this time it will be a bit of a smaller penalty than some other times, five places and, for sure, I can still have a good race from there,” Bottas said. “The main thing for me, I think, is to focus on the race pace and that’s what we tried to focus on today, especially in FP2.

“There’s still a lot of work to do with the setup, it’s not easy to drive at all, as it feels like in some places this track has lost quite a bit of grip, and then the balance is a bit inconsistent.”