aThe Reds were outplayed for much of the first leg of their last-16 clash in Paris last week, but managed to grab a 1-0 win thanks to a late goal from Harvey Elliott.
It was a significant result, but Slot is aware that it must be followed up with a strong display at Anfield on Tuesday.
"Yes. I do think so," Slot responded when asked if Liverpool need to be better than ever in any of his matches so far this season.
"This is the toughest team we've encountered up to now.
"We've played against Arsenal and Manchester City, and although the margins were small, the intensity PSG play with, combined with their quality-being one of the wealthiest clubs - and their top-notch manager, makes them a very difficult team to face."
Liverpool have only suffered one defeat at Anfield this season, a 1-0 loss to Nottingham Forest in September.
However, Slot insists his team will not take a defensive approach against PSG in an attempt to avoid a second home loss this season.
"We approach every game with the aim of winning," he said.
"That's what we tried to do last week as well-it wasn't our plan to be so deep for most of the match.
"(On Tuesday) we aim to play a different kind of game, but the intention remains unchanged-we're not aiming for a draw."
Cody Gakpo, the forward, is now available for selection after recovering from an injury.