Tom Tancredo, a Republican congressman and presidential candidate, said that the US cannot trust the Mexican government in combating narcotics and called the neighbouring country a "drug cartel".
"Mexico is a drug cartel," Tancredo said on Wednesday. "The degree of corruption inside the government and the military is so great that it's hard to see where the government ends and where the cartels begin."
Tancredo spoke during the testimony of Assistant Secretary of State Tom Shannon, who was briefing Congress on a proposed $1.4 billion, three-year aid package to the Mexican government to step up efforts to halt the flow of marijuana and cocaine into the US.
Congress has been lukewarm about the proposal and criticised the State Department for not adequately briefing lawmakers prior to reaching the deal with Mexico. The ranking member of the centre-right Republican Party on the House Foreign Affairs Committee quickly chastised Tancredo for his remarks.
"Saying that Mexico is a drug cartel is an insult to the Mexican people, the Mexican government and the cooperation between both countries," Representative Ileana Ros-Lehtinen said.
The Mexican government also took exception to Tancredo's comments.
"These are characterisations based on unfortunate clichés and stereotypes, which are far from reflecting reality of Mexico, and are as wrong as saying that all Americans consume drugs," said Ricardo Alday, a spokesman for Mexico's embassy in Washington.
Tancredo, who represents a congressional district in Colorado, is considered a long shot to win the Republican nomination for the presidential election.