MEXICO CITY – For decades, Cancun has sold itself to Americans as a slice of Americana with a Caribbean beach and 18-year-old drinking age. Signs are in English. The dollar is king. Streets are safe, lawns are groomed, buildings are modern.

Now, U.S. and Mexicans authorities are concerned over the encroachment of imperfect Mexico on the nation’s No. 1 resort, a fantasy land of hotels, restaurants and night clubs.

The U.S. State Department issued a travel warning after the City Council resigned this month and the mayor was ousted in the larger municipality of Benito Juarez, where most locals live, speak Spanish and use the peso. Cancun lies within Benito Juarez.

U.S. authorities expressed concern over violent demonstrations following the political power struggle earlier this month, as angry city workers demanded to be paid and the ousted mayor, Juan Ignacio Garcia, set up what he called a “parallel government.”

“Americans traveling to Cancun should use caution and avoid crowds, especially around the city hall and the Plaza de la Reforma, as there is a potential for spontaneous violence,” the U.S. travel warning stated.

Street protests are common in Mexico – and in such resort cities as Acapulco and Puerto Vallarta – but not in picture-perfect Cancun. Locals refer to the resort as the “hotel zone” to distinguish it from the neighboring city, which draws few foreigners.

Previous State Department travel warnings for Cancun have focused on the dangers of excessive drinking, sexual assault by other tourists and a local serial rapist – who police later said was caught.

Mexican authorities, on the other hand, are alarmed about the latest U.S. warning and the perception that the nation’s political tumult could affect tourism.

On Tuesday, Interior Minister Santiago Creel, Foreign Minister Luis Ernesto Derbez and Tourism Minister Rodolfo Elizondo asked the U.S. State Department and the U.S. ambassador to Mexico, Tony Garza, to repeal the warning.

“We talked with the American State Department, and we indicated that this is a local political issue that is being resolved and will have no effect … on the vacations of foreign tourists,” Derbez told reporters.

The head of the NH hotel chain in Mexico, Francisco Medina, said the political turmoil in Cancun has not affected tourism there but could if it is not resolved in coming weeks and months.

“This could become a problem if the disturbances continue,” Medina said from the chain’s hotel in Cancun. Right now, he added, “Hotel occupancy is at its upper limit.”