The Ligue 1 champion has signed Hugo Ekitike from Reims but saw Angel Di Maria depart on a free transfer, while Galtier confirmed Arnaud Kalimuendo is closing in on a move to Rennes.
PSG may still have Neymar, Kylian Mbappe and Lionel Messi to lead the line, but a long and gruelling season – which is complicated by the World Cup in Qatar – has Galtier wanting to increase the depth in his attack.
"Yes, we would like to bring in another forward. We have a very busy schedule, so we would like to bring someone in," he said.
"The club is working hard on that. I am in constant contact with Luis Campos [PSG football advisor], the board and the president. We must not make any mistakes. We must not rush things. We have to do something realistic.
"There are no guarantees. I know the club won't sign anyone for the sake of it. It would need to be someone who can really bring something to the squad and that is what the club are working on."
Another forward edging towards the exit is Mauro Icardi, with Galtier adding that the club are exploring options for the Argentina international regarding a transfer.
"It has not been easy. His absence from the squad last week was down to a sporting choice, I saw him at the start of the week to say that I am going to make the squad smaller. I am not going to work with 25 players," Galtier explained.
"Whether he has offers that he might like, I don't know. The club is working on that, we're working with Icardi to find the best possible solution. He had very little playing time last season and I think it is important for him to do that.
"Whether he wants to play in the Champions League specifically, I don't know. In the interest of the club, we want him to find the best solution, which is a club where he can show his quality.
"He has had a tough couple of years and with his experience playing somewhere different and having a better atmosphere, that might allow him to get his career going again."