Attorney General Eric Holder said Tuesday that the controversial tactic that allowed illegal guns to be smuggled to Mexico "should never have happened, and it must never happen again."
In testimony to the Senate Judiciary Committee, Holder hit hard at the Bureau of Alcohol, Tobacco, Firearms and Explosives practice that has tainted his tenure at the Justice Department and led to some Republican calls for him to resign.
"I want to be clear: Any instance of so-called 'gun walking' is unacceptable," Holder said of weapons smuggling, later adding: "This operation was flawed in its concept, and flawed in its execution."
Holder acknowledged what critics have been saying about the long-term consequences of "gun walking."
"Unfortunately we will feel its effects for years to come, as guns that were lost during this operation continue to show up at crime scenes both here and in Mexico," Holder said. "We are losing the battle to stop the flow of illegal guns to Mexico."
Holder defended his own actions, reminding the panel he called for the inspector general to examine the so-called Operation Fast and Furious and issued a directive that "gun-alking" was illegal and should never be repeated. The resulting report may be concluded before the end of the year.
However, Holder stopped short of laying blame for the flawed operation.
Last week, his assistant attorney general, Lanny Breuer, expressed "regret" for his failure to alert Holder about a similar earlier operation called "Wide Receiver" which had employed similar ATF "gun-walking" tactics during the Bush administration.
At the hearing Tuesday, Republican Sen. Charles Grassley of Iowa said, "It doesn't matter how many laws we pass if those responsible for enforcing them refuse to do their duty -- as was the case in Fast and Furious."