The Reds came into the game off the back of a 5-2 thrashing of Roma in the Champions League and retained two-thirds of their forward line, but appeared lethargic as the relegation-threatened Potters held on for a potentially precious point.
Klopp was stoic about the result as he reflected on a bad day at the office for his team.
“Frustrating? I’m not sure, it is how football can be,” Klopp said at his post-match press conference, quoted by Liverpool's officlal website.
“We met Stoke in the moment when they thought a point could be enough [to stay up], but if they think they can win the next two games and have a chance with that then we cannot change that opinion.
"But you saw it in the game if you don’t take the lead then... we had two opportunities for that - a fantastic chance for Mo."
The Salah chance was the best of the game and came after just five minutes, when he chipped wide of Jack Butland's goal after latching onto a Jordan Henderson through-ball.
Klopp also reflected on the other key talking point, which occurred in the dying embers of the game. A Georginio Wijnaldum cross struck the outstretched arm of Pieters but Andre Marriner waved away the appeals with Anfield baying for penalty.
Klopp told BBC Sport it looked a "clear" penalty and said that his side "should have got more penalties" in the league this season.
"So at the end it’s not the best day of my life but I had for sure worse days," the German concluded. "Let’s take it like this, let’s recover and go to Rome.”
The second leg against Roma takes place on Wednesday evening.