Klopp was speaking pitchside after watching his team beat Tranmere Rovers 4-0 at Prenton Park on Wednesday night courtesy of penalties form James Milner and Ben Woodburn as well as a long range effort from Marko Grujic and a tap in from Pedro Chirivella.
He was asked if he had a message for supporters who have grown nervous about the Reds' lack of further activity in a window.
The Reds boss told the Liverpool Echo: "We also bought players. Yes and they (rivals) lost a lot of players. I heard Man United lost players, got new players. Don't know about Chelsea, I've not heard a lot.
"If any of our fans think about what the other teams are doing and why we aren't doing anything, I can't help, sorry. We cannot only buy players because other teams buy players.
"We do our business as good as we can do it and we are completely in it and we are convinced about the way that we are going so that's all.
"Nervous fans? Sorry I cannot help, I don't have to write a message for this.
"I'm not nervous - maybe that's the right message for this."
Asked again about the possibility of new players arriving, Klopp joked: "There's no chance we will add any more players and I'm not frustrated about this - joking!
"We have until August 31, we have time and sometimes things need time. We'll do transfers because we want to do them, if not it's because we don't want to do them. So we have to wait a bit but tomorrow you can have a long sleep because nothing will happen tomorrow."