LA Times: "Mexico says U.S. never told it tracked guns were passing border."

The statement says Mexico would never have allowed arms to enter the country as part of the operation under which U.S. agents permitted the purchase of weapons to build more sweeping criminal cases.

Ken Ellingwood reporting from Mexico City:

Mexican authorities say they were aware of the U.S. anti-gun operation that allowed smugglers to buy weapons under the watch of agents in the United States, but that they had no idea that the program allowed weapons to be smuggled into Mexico.

In a statement issued late Thursday, Mexico's federal attorney general's office said Mexican officials were advised of operations north of the border against suspected traffickers. But the Mexican agency said it "had no knowledge of the existence of an operation that might include the transgression or controlled trafficking of arms to Mexican territory."

The attorney general's statement said Mexico would never have given permission for weapons to enter the country as part of Operation Fast and Furious, under which U.S. agents permitted the purchase of weapons to build more sweeping criminal cases against crime bosses.

"The government of Mexico has not given nor will it give its authorization, tacit or express, under any circumstance, for that to occur," the agency said in the most extensive comments the government has offered on the matter so far.

A statement issued by the U.S. Embassy here Thursday said American officials had kept Mexican counterparts informed "as plans unfolded on operations in the United States" through Jan. 25, when 20 suspected weapons traffickers were arrested in Arizona. On Friday, the embassy said there was "no contradiction" between the Mexican statement and information provided by American officials.

The 15-month operation, carried out by the Bureau of Alcohol, Tobacco, Firearms and Explosives, became public after guns sold to suspected smugglers in the U.S. turned up at the scene of the fatal shooting in December of a Customs and Border Protection agent, Brian Terry.

Some ATF agents were already alarmed as evidence mounted of weapons making their way into the hands of drug cartels in Mexico.

At least 195 weapons sold in Arizona have been recovered in Mexico, and one ranking Mexican congressman claims the smuggled guns have been tied to the injuries or deaths of as many as 150 people.

Angry Mexican politicians from across the spectrum have blasted the U.S. effort as a violation of their country's sovereignty. Lawmakers have called for investigations and hearings into whether Mexican officials were aware of the program.

The Mexican statement praised U.S. Atty. Gen. Eric H. Holder Jr. for launching an investigation into the operation. Holder said that "letting guns walk … is not something that is acceptable."

But in the United States, there are concerns about Holder's decision to delegate to the Justice Department's inspector general responsibility for conducting the probe, already underway. One of the key ATF whistle-blowers to have complained about the gun-running operation was ignored when he originally sought the inspector general's intervention.

In a letter this week to the integrity committee of the Council of Inspectors General, U.S. Sen. Charles E. Grassley (R-Iowa), who is probing the Fast and Furious operation as the ranking member of the Senate Judiciary Committee, said the Justice Department's own role in supervising the operation must also be part of the investigation.

"Given that the [inspector general's office] initially failed to follow up, it might have an incentive to minimize the significance of the allegations in order to avoid the appearance that its own inaction contributed to the problem in the last few months," Grassley wrote.