The warning states that Americans should defer non-essential travel to four entire states and parts of 10 others, including the state where Acapulco is located, suggesting that visitors to that resort exercise caution and stay within tourist areas.
More Americans travel to Mexico each year than to any other country. Ten million went there last year alone. While the State Department's latest advisory acknowledges that most do so safely, it also spells out exactly where Americans should and should not go.
The new warning comes just before the all-important spring break travel season.
"I do have some concerns," said Mike DeMarco, who is planning at trip to Puerta Vallarta, Mexico. "I just wanted to get an expert's opinion."
Though DeMarco has been to Mexico many times before he went to his travel agent for advice Tuesday. The State Department's latest travel warning has him worried.
"I just want to find out before we make a decision," he told ABC7.
Alfonso Sumano is the regional director of the Mexico Tourism Board. Sumano applauds the warning for being so precise.
"You know very well that if you're planning to go to Mexico and you're going to one of our wonderful destinations, you are actually not included in that advice," said Sumano. "Mexico is still the number one destination for Americans traveling abroad."
The State Department's advisory cites the ongoing war between drug traffickers and the police and military as the main reason for their alert.
According to the advisory, 120 Americans were killed in Mexico last year alone. But the vast majority of the violence is confined to parts of the country where tourists do not go.
"Anyone that would be backpacking through Mexico or doing smaller towns, that would be one issue that would potentially have some problems," said Mark Janus of Janus Travel in Norwood Park on Chicago's Northwest Side.
A substantial part of Janus' business is all-inclusive trips to Mexican beach resorts. He says quite a few people ask about safety but he has not had any cancellations so far.
"We usually let them know that if they are concerned about it, the issue would be that as long as they're not going out and exploring late at night or doing anything that you wouldn't do in a city that you're not really familiar with, you'll probably be fine," said Janus.
Despite travel warnings that have been around for some time now, nearly 22.6 million people of all nationalities visited Mexico last year.