The disgruntled Dutchman made the claim after coming third in the Spanish Grand prix.
Five races into the F1 calendar and Verstappen has already secured his second finish in the top three, but Red Bull have struggled to bridge the gap to Mercedes so far this season.
Mercedes stars Lewis Hamilton and Valtteri Bottas have been superb this year, and have secured one-two finishes in each of the opening five races, something never done before.
The Silver Arrows have claimed pole position for all-but-one of the five races so far, as Charles Leclerc had top spot in Bahrain.
Hamilton now leads the Drivers’ Championship and is on 112 points, 46 points ahead of Verstappen in third.
And the Red Bull star admitted after falling behind in Spain that he can’t see Mercedes being caught for the time being.
“Qualifying was quite good, we were close behind Ferrari,” he told AutoSport.com.
“Mercedes was way too quick, but generally we could be quite satisfied.
“Of course, personally I always want to win and finish first, but that is not achievable now.
“In the end we were on the podium after the race, so that is fine.”
The next race in the calendar is the Monaco Grand Prix on May 26, but Verstappen is still not confident that Red Bull will be able to keep the pace.
“Personally I do not think [Red Bull will be one of the favourites in Monaco],” he continued.
“If you look at the last sector in Barcelona, then Mercedes is really very quick, so they will go there as favourites.
We’re not really better in any corner than Mercedes.
“It’s good – it’s not that it’s a bad car – but at the moment the Mercedes is just quicker than us everywhere.
“Medium-speed, high-speed is pretty similar but that depends a lot on the downforce levels you’re running every single weekend so it’s a bit difficult to say.
“On this track, they were very strong in the low-speed corners. And that is normally pretty good for Monaco [the next race] as well.”