The boss knows he must revamp his squad but said it will take time with Villa bottom of the Premier League.
Villa signed 13 new players in the summer under former boss Tim Sherwood but are 11 points from safety having failed to win since the opening day.
Chief executive Tom Fox and sporting director Hendrik Almstadt were in New York on Monday to meet owner Randy Lerner to talk about transfer plans.
Villa host Crystal Palace tonight (7.45pm) and Garde conceded, despite their summer spending, he will need to overhaul the struggling squad again.
He said: “January is not the best time to do things because it is very difficult for many reasons.
“Attracting players in the situation we are in is not an easy task because players are not only attracted by money as many people think.
“They also care about the project that we present to them. I have to say that if we had been in a better position I would probably already have signed at least two players,” he said.
Garde, who wants to sign Arsenal’s Mathieu Debuchy and Chelsea’s Loic Remy, confirmed he has already lost out on players because of Villa’s desperate position.
“Yes. It is very frustrating but I came into a situation that I knew could be uncomfortable to me or for signing players,” he added.
Crystal Palace will be missing Yannick Bolasie but Connor Wickham is back in Palace’s squad after returning to training following a calf injury.