Klopp's side will face Borussia Dortmund in the 2018 International Champions Cup on Sunday. The Liverpool boss was asked about Pulisic ahead of the match, per Kristian Walsh at the Liverpool Echo.
He said: "If–at one point–he will join us, I don't know. I like him, it's not that that could be the problem, but we respect contracts still and there's no market I know about at the moment. We did our business and Dortmund are doing theirs. All good."
Liverpool have twice tried to land Pulisic and saw an £11 million bid rejected in 2016. They could try to sign him again this summer, according to Darren Lewis and Alex Richards at the Mirror.
Pulisic is still only 19 and has emerged as one of the most valuable young players in the world:
The teenager made 32 Bundesliga appearances for Dortmund last season, contributing four goals and five assists as the team finished a disappointing campaign in fourth place.
More will be expected from the club next season under new manager Lucien Favre. The Dortmund boss was impressed with Pulisic in their International Champions Cup win over Manchester City on Friday.
Pulisic started the game and won the penalty from which Mario Gotze netted the only goal of the game against the Premier League champions.
"[Christian Pulisic] played extremely well today," he said, per Austin Lindberg at ESPN FC. "He knows exactly when he has to accelerate, which he showed three or four times today. His dribbling on the right wing was superb. He has a lot of ambition and is still very young–he's a very good player."
Liverpool have already spent heavily in the transfer window bringing in Fabinho, Alisson and Xherdan Shaqiri. Naby Keita has also arrived after a deal was struck with RB Leipzig in August 2017.
Klopp has said he does not think the club will sign any more players this summer, per Goal's Neil Jones:
However, the club remain linked with a move for Lyon's Nabil Fekir. He could still join the Reds this summer if the two teams can agree a deal, according to L'Equipe (h/t Naveen Ullal at Sport Witness).