Hartley not focused on Toro Rosso return

Hartley completed his maiden Formula 1 race in 13th position out of 16 places, as he was replacing Pierre Gasly at Toro Rosso.

The Kiwi driver said he "just did the job" instead of inquiring about whether he can stay for more Formula 1 race with the time.

"Up until this moment I haven't been asking the question," said Hartley, who finished three positions and 27 seconds behind teammate Daniil Kvyat.

"And it was the same when they called me up to do a simulator test. I didn't want to know, I just did the job, and that's how I've taken this weekend.

"I've actually been really relaxed and I'm happy I did it that way. I guess now there might be some conversations. I really don't know. You'll have to ask them."

"Going into the darkness" in race

The United States grand prix was Hartley's first single-seater outing in five years.

He admitted that his lack of experience in F1, as well as with the Pirelli tyres, made it unclear how his race would go.

"So much to learn. It was the first time I've put 20 laps on these Pirelli tyres, it was going into the darkness in terms of what was going to happen," Hartley added.

"So many experiences I can take going forward, if I get an opportunity. At the end of the last stint I started to understand a bit more, and was pretty happy with the performance.

"There's always things you can do better. If I was to do the race again tomorrow, with the experience I've gained, I would do some of it a bit differently."

He admitted that he hadn't made the best start, and also lost time while getting "stuck" behind Lance Stroll.

"My start wasn't very good, I didn't nail that. I nailed some of the practices, but when it came to the real one, it's been a while since I've done one. I'm pretty happy with the first lap, there was a bit of a tussle with Stoffel.

"I was a bit disappointed that Stroll passed me after the pit stop and I got stuck behind him. We had good pace in the car but then I was stuck, and he did a good job to make the pass.

"That's another lesson learned, I should have got on the overtake button, but I thought he was far enough behind. Managing tyres, I think I was probably too conservative."