Mexico's Foreign Secretary Patricia Espinosa regretted that "outdated visions" on drug trafficking continue to be used and urged U.S. officials to refrain from commenting on issues they are not fully informed about.
"These unfortunate incidents should show that officials need to refrain from making statements, from giving opinions without having all the facts," Espinosa said.
Westphal made his initial remarks Monday at the Hinkley Institute of Politics Forum. In a statement Tuesday he said that in response to a question, he "mistakenly characterized the challenge posed by drug cartels to Mexico as 'a form of insurgency.'"
"My comments were not and have never been the policy of the Department of Defense or the U.S. Government toward Latin America," he added. "I regret that my inaccurate statements may have caused concerns for our partners and friends in the region, especially Mexico."
Espinosa said the two countries "need to find cooperation mechanisms that lead to a greater ability to confront organized crime."
"It's totally unacceptable and inappropriate to see the problem unilaterally," she added.
The Mexican Interior Department said in a statement late Tuesday that it "categorically rejects" the comments by U.S. Undersecretary of the Army Joseph Westphal.
"It's regrettable that this official makes statements ... that do not reflect the cooperation that the two governments have been building," the statement said.
It is not the first time Mexico has accused U.S. government officials of exaggerating the situation in Mexico. Last year, President Felipe Calderon protested after U.S. Secretary of State Hillary Clinton said Mexico resembled Colombia two decades ago, when drug traffickers controlled sections of that country.
Drug gang violence in Mexico has reached unprecedented levels since Calderon deployed tens of thousands of troops and federal police to trafficking hot spots four years ago, vowing to crush brutal cartels.
The fighting has at times taken warlike proportions, with cartel gunmen ambushing army patrols, staging elaborate roadblocks and carrying out horrific massacres.
Nearly 35,000 people have been killed.
But the Interior Department said the violence could not be characterized as a rebellion.
"Organized crime is seeking to increase its illegal economic benefits through trafficking of drugs and people, homicide, kidnapping, robbery, extortion and other crimes," the statement said. "They are not groups that are promoting a political agenda."