Guardiola won 14 trophies during his time in charge at Barcelona, before picking up three consecutive Bundesliga titles and two German Cups in a three-year spell at Bayern Munich.
But former Borussia Dortmund head coach Klopp feels that winning silverware in the Premier League is much harder.
"The competition makes it really interesting. Winning the title in England is the biggest challenge of them all," Klopp told the media.
"If you are three times in a row Spanish champions, three times in a row Bundesliga champions, then you think okay, let's try something else. If you are looking for the biggest challenge, then you need to go to England."
The German continued: "It's not easy in Germany. If you want to be in front of Bayern Munich, you have to win all the other games and then a minimum of one against Bayern. They don't lose.
"In this country it's a very different kind of difficulty. Here you have a number of clubs who think they should be number one."
Guardiola, who has added Leroy Sane, Nolito and Ilkay Gundogan to his squad, will start his City reign against Sunderland at the Etihad Stadium on August 13.