Verstappen moved back ahead of Hamilton in the title race with a second-place finish at the Turkish Grand Prix.
Hamilton could only finish fifth after starting the race from 11th on the grid following an engine change and subsequent grid penalty.
Since the British Grand Prix, Mercedes has enjoyed the advantage over Red Bull, with the race in Zandvoort the only time where Verstappen could control the race from the front.
“They were definitely quicker this weekend,” Verstappen said in the post-race press conference. “We just didn’t get it together and also in the wet they seemed to have a bit of the edge as well.
“So we’ll have to analyse of course why we weren’t that competitive here and I definitely do think they probably stepped it up a bit more so yeah, even with the points, it’s not going to be easy but… I saw, you know, I think I even said it before we even started the weekend, so far we’ve had a really good year so it’s not going to change the world for me if we finish first or second at the end of the day, but I’m always going to give my best and we’ll see again in Austin how it’s going to go.
“We won’t give up, we’ll always try to do the best we can and hopefully, of course, at the end of the championship it’s going to be enough but if it isn’t I’m not going to be sleepless.”
F1 returns to Austin for the United States Grand Prix next time out, with Red Bull not winning at COTA since 2013.
Assessing its chances in America, Verstappen said: “A lot of flat-out sections as well, tyre wear is quite high as well, so there are a few things to look into. I think maybe at some other tracks we can maybe be a bit better, but it’s never going to be very easy.
“The whole year already has been quite close, of course. Sometimes it looked like maybe we were a bit better but then sometimes also they were quite quick. I just hope that from the remaining races there are a few tracks, of course, or more than half, are better for us but we’ll find out.”