MEXICO CITY — Not long ago, any suggestion that Mexico might walk away from the North American Free Trade Agreement would have been met with utter disbelief.

That was before Donald J. Trump was elected president of the United States.

Free trade is a mantra of Mexico’s political elite, the core of the country’s development strategy.

But now that Mr. Trump has said he wants to renegotiate Nafta, a growing number of Mexican officials and businesspeople are asking what price is worth paying to stay in it. Many of them are concluding that Mexico could have more to lose from years of haggling and economic uncertainty than from simply opting out.

“There could be no other option,” Mexico’s economy minister, Ildefonso Guajardo, said on Tuesday in a televised interview. “If we go for something that is less than what we have, well, then there is no sense in staying.”