Guardiola has been in charge of Manchester City since 2016 and last month signed a new contract until the summer of 2025.
The 51-year-old has won four Premier League titles, four League Cups and one FA Cup but is yet to bring Europe's biggest trophy to the Etihad Stadium.
The Premier League champions lost last year's final to Chelsea and will face RB Leipzig in the round of 16 stage of this season's competition.
They were on the verge of making another final earlier this year before a late capitulation against Real Madrid saw the Spanish side advance.
"I admit it's the trophy that we want and of course it would not be complete – my period here – if we don't win it," Guardiola told reporters ahead of City's EFL Cup clash with Liverpool.
"But it's not the only reason I extended the contract, absolutely not. What does it mean if for the last 11 months we didn't play in the Champions League?
"Of course, I will do everything in this time we are together, we are going to try, as we tried before. Of course it's the trophy we don't have and we will try to do it."
Guardiola won the Champions League twice during his time as Barcelona manager, with his last triumph in the competition coming in 2011.
