The Reds were the best runners-up in Premier League history this season by finishing with 97 points, one behind City.
"We are a tight-knit group, a young group," said 25-year-old Robertson.
"Hopefully we will be here for many years and we will be a better team in terms of maturity and experience next year.
"Man City know, hopefully, we are here to stay. We know they are definitely here to stay, they are incredible.
"Fingers-crossed we don't lose anyone. We will go into next season as strong as ever. Whether we can put in the performances remains to be seen but we hope we can."