Verstappen wrapped up his third world championship in a row with a second-place finish in the Qatar Grand Prix sprint race on Saturday.
The Dutchman’s sheer dominance was underlined by the fact he has put the championship out of reach with six grands prix remaining, having won 13 of the 16 races so far.
Russell acknowledged Verstappen and Red Bull’s superiority this year and admitted Mercedes have a lot of work to do if they are to turn things around next season.
“A huge congratulations to him and Red Bull,” Russell told Sky after finishing fourth in the sprint.
“From the outset, Red Bull were far superior to everybody else and then Max has then obviously been on another level recently. So we can only congratulate him.
“We’ve got to look at ourselves in the mirror and raise our game to give them some trouble next year, because nobody likes to see that dominance.
“And we want to be there in the fight and putting them under a bit of pressure.”
Earlier in the weekend, Russell stated he is "extremely confident" that Mercedes won't "trip up" in their pursuit of Red Bull.
Lewis Hamilton has already stressed that Mercedes need to pull off the greatest six months of development in their F1 history to challenge Red Bull next year.