The seven-time grand prix winner, who raced in F1 from 2001-2006, believes running a team from the US cannot work.
Speaking at last weekend's Long Beach IndyCar event, Montoya said: "If he wants to build [the team] here in the States I think it's completely mad.
"You can't even call it mad because it makes no sense.
"You are not going to get people from England to move to Charlotte."
Can Haas succeed where USF1 failed?
Montoya, who has returned to single-seater racing in IndyCar this year after racing in NASCAR since leaving F1, has also warned the sport against turning its back on its European roots.
"I think Formula 1 has to be careful not to discard Europe too much," he added.
"That is where the original fans are, where the car fans are. You don't want to keep driving away from Europe.
"I know other places will give them more money to go but if you take the British GP, or the Spanish GP away, imagine that.
"There are a lot of big races and you don't want to screw that."
HAAS ACCEPTS DOUBTERS
During a press conference on Monday, Haas said he understood why many outsiders have doubts about his team.
"There is obviously scepticism in anything that anybody's trying to do that hasn't been done before," he said.
"The only way I can allay that is to go out there and do it. I think we have the flexibility.
"When things don't go right, we go in a different direction, and we do whatever it takes to get things done.
"I can't tell you about the other people that fail. I don't know why they fail.
"Maybe where they failed, I can figure out how not to. But I firmly believe that we have the right tools to go forward on this and be successful at it.
"I've been pretty successful at taking on projects that other people say you can't do."
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