The Reds have recruited heavily under the German this summer, with the former Borussia Dortmund man determined to bridge the gap between his side and title-winners Manchester City.
Klopp has brought in Naby Keita, Fabinho, Xherdan Shaqiri and goalkeeper Alisson, while he also admits one more may join before Thursday's transfer deadline.
Liverpool will start the season against West Ham on Sunday and Klopp is expecting another tough campaign, despite his new arrivals.
'The league will be difficult,' Klopp told the Liverpool Echo.
'It is not about judging our situation and thinking 'wow, really good'. We need to be ready each week, not only for a few games. That is our challenge.'