The announcement is a major blow for Mexico's economy. Tourism is Mexico's second-largest industry. About 60 percent of Mexico's visitors are American, and about one third of them are either Texans or travellers who pass through Texas.

The advisory comes despite pleas from top Mexican officials to limit the travel warnings to specific areas where the threat of violence is greatest.

Mexican officials said that popular tourist areas such as Cancun and Cabo San Lucas are safe for American travellers.

Drug violence has claimed an estimated 40,000 lives in Mexico since 2006.

"The Mexican government has made great strides battling the cartels, and we commend their continued commitment to making Mexico a safer place to live and visit," Texas Department of Public Safety Director Steve McCraw said. "However, drug cartel violence and other criminal activity represent a significant safety threat, even in some resort areas."

The number of Americans murdered in Mexico jumped to 120 last year from 35 in 2007, McCraw said.

"Many crimes against Americans in Mexico go unpunished," he said.

Some crime in Mexico is directly related to cartel violence, and some is not, but rape is a serious problem in resort areas, said Tom Vinger, a spokesman for the Texas department.

"Some bars and nightclubs in resort cities like Cancun, Acapulco, Mazatlan, Cabo San Lucas and Tijuana can be havens for drug dealers and petty criminals," Vinger said.

Mexican officials said they are deeply concerned about Texas' advisory.

"This warning is exceptionally aggressive," said Rodolfo Lopez Negrete, chief operating officer of the Mexico Tourism Board. "To paint Mexico with such a massively broad brush stroke is simply outrageous."

Lopez Negrete met with several Texas state officials and told them that the drug cartel violence is largely confined to isolated areas along the Rio Grande in northern Mexico, including the city of Juarez across from El Paso.

He urged the state to stress that the violence is not widespread, and that of the 22.7 million tourists who visited Mexico last year, almost none were in the vicinity of any type of violence.

"Those pockets where this violence is taking place are very well identified," Lopez Negrete said during his visit to Texas last week. "This is totally unrelated to tourism. This is not about attacking tourists."

(Reporting By Jim Forsyth; Editing by Corrie MacLaggan and Eric Beech)

• A Permanent Economic Emergency