Verstappen enjoyed a legendary 2023 campaign, winning 19 of the 22 races in F1 2023.
Despite enjoying an unprecedented year, Marko think there’s still more to come from Verstappen and Red Bull.
"In all areas. It's in his absolute will to win,” Marko told Sky Germany. “He can go to extremes in any situation. As soon as he learns that there might be a penalty for an incident, he increases his lead by 10 seconds.
“He simply instantly gains a second per lap. And he does that cleanly and with ease.
"He is decisive in terms of tyre management. Max can drive incredibly hard and at the limit without overloading the tyres. He almost reads the tyres.
“That was again the case during qualifying in Abu Dhabi - in which he again went a step further than everyone expected. That's why I think we haven't reached our peak yet."
Marko also praised Honda for their contribution in Red Bull’s success, particularly as Verstappen finished every race in 2023 without a mechanical issue.
"He [Verstappen] is very confident, but no longer fights when he doesn't need to and yet he does just keep getting faster, and handles the material well,” Marko added.
“But all this I never thought possible and that is why I don't see any limits at the top at the moment."
"I thank our staff in England and at Honda. Honda made an incredibly competitive engine. In addition, the engine was stable, also in terms of fuel consumption.
“But such an achievement is only possible in a team where everyone works with full passion, dedication and enthusiasm.
“And I think that is characteristic of our team. We concentrate on ourselves and make sure that we win as many races as possible."