Guardiola said this ahead of Man City’s Premier League clash with West Ham United on Wednesday.
Guardiola’s men will take on Real Madrid in the Champions League round of 16 first-leg tie on February 26.
Man City have never progressed past the quarter-finals of the Champions League under Guardiola, and they were beaten by Tottenham Hotspur at that stage last season in a dramatic encounter.
Speaking in an interview with Football Daily, the Spaniard said:
“I want to win the UEFA Champions League.
“Let see what we can do against Real Madrid in the last 16 ties.
“It will be the happiest seconds of my career if Man City beat Madrid and progress to the next round, I want to dream.
“But if we do not defeat Real Madrid, then Man City’s Chairman or Sporting Director will say to me; ‘We did not do well, we wanted to win the UEFA Champions League, and now I am going to sack you from your post’.
“A lot of times it has happened and sometimes he will say ‘OK you have done well, but what can we do to improve?’”.