on february 8 , 2012 , the u.s. department of state , bureau of consular affairs , issued the following travel warning ( in part ) : the department of state has issued this travel warning to inform u.s. citizens about the security situation in mexico ... u.s. travelers should be aware that the mexican government has been engaged in an extensive effort to counter transnational criminal organizations ( tcos ) which engage in narcotics trafficking and other unlawful activities throughout mexico .