Guardiola admitted that the club may never win the Champions League during his tenure after coming up short in previous seasons.
He said: "Football always gives you another opportunity. People always said that until you win the Premier League you can't be considered one of the greatest, now it's the Champions League. That's fine I accept this challenge.
"If it doesn't happen next season, it will be the next season, and if it doesn't happen next season it will be the next season.
"With me, without me, with this group or without this group it is important we are there fighting for that and maybe one day it happens.
"If it doesn't happen, we are unlucky and we tried. It's important to be there all the time and do it."