The Premier League champions had looked favourites to sign German striker Timo Werner from RB Leipzig before the 24-year-old opted for Chelsea.
Klopp said the upcoming transfer window was likely to be more subdued than in previous years due to the impact of COVID-19 on clubs' finances.
"COVID has influenced both sides with ins and outs, that is completely normal, and it's just not likely that it'll be the most busy summer in the world," he told reporters.
"We can't spend millions and millions because we want to, or we think it's nice to do. We never wanted that.
"The problem with a strong squad is how do you improve a strong squad in the transfer market?" Klopp added.
"You have to be creative... We try to find solutions internally and there's still a lot to come: we have three or four players who can make big steps." (Reporting by Shrivathsa Sridhar in Bengaluru; Editing by Peter Rutherford )