The two continental powerhouses will meet for only the third time ever at Anfield on Wednesday, with the only two meetings before that coming in the 2005 and 2007 finals.
The Rossoneri are making their return to the Champions League after an eight-year absence, and Klopp believes that the visit of Stefano Pioli's side will be "very tough" for both clubs.
"2005 I have more in my mind than 2007. If you think of any kind of European battles, Liverpool against AC Milan is a must-watch," Klopp said at his pre-match news conference.
"Milan have not been in the Champions League for a few years. They had a brilliant season and have started this one really good as well.
"It will be a very tough game for both sides. There are few nice games in this stage of the competition and this is one of them."