Attorney General Eric Holder testifies during a Senate Judiciary Committee Hearing about the controversial the "Operation Fast and Furious" gun running program on Capitol Hill, on November 8, 2011 in Washington, DC. (Mark Wilson/GETTY IMAGES)

Attorney General Eric H. Holder Jr. told Senate Republicans on Tuesday that the Justice Department provided “inaccurate” information to Congress on the “Fast and Furious” gun-trafficking sting and said that his congressional testimony about when he learned of the controversial operation had been imprecise.

Holder said that a Feb. 4 letter to congressional investigators, in which the department denied allegations that agents had allowed guns to flow illegally onto U.S. streets and into Mexico, was wrong. He said Justice officials learned only some time after they sent the letter that the tactic, known as “gun walking,” had been extensively used in the Phoenix-based Fast and Furious.

“The information in that letter was inaccurate. That letter could have been better crafted,” Holder told the Senate Judiciary Committee. Blaming the mistake on bad information supplied by the Bureau of Alcohol, Tobacco, Firearms and Explosives and the U.S. attorney’s office in Phoenix, Holder said: “That’s something I regret.”

Under gentler questioning from Sen. Patrick J. Leahy (D-Vt.), the committee chairman, Holder also acknowledged the imprecision of his May 3 testimony. At that hearing, he said he “probably heard about Fast and Furious for the first time over the last few weeks.”

On Tuesday, Holder amended his recollection, saying that he had actually learned about the program at the beginning of this year. “I should probably have said a couple of months,” said Holder, who defended his overall handling of the controversy as “responsible” and made it clear that he has no plans to resign, as some Republicans have urged.

It was unclear whether the attorney general’s partial mea culpa will ease concerns over his handling of the gun-trafficking operation that is under investigation by Republican lawmakers and the Justice Department’s inspector general. Fast and Furious, which began in 2009, allowed small-time straw purchasers to pass firearms to middlemen, who trafficked the guns to Mexico. Anger over the tactics, which resulted in more than 2,000 illegally purchased firearms hitting the streets, has led to the reassignment of ATF’s former acting director and others and the resignation of Arizona’s U.S. attorney.

Republicans are pushing to learn whether senior Justice officials were aware of the details of Fast and Furious, and they have questioned whether Holder was truthful in his May 3 testimony. Sen. Charles E. Grassley (R-Iowa), who has led the probe in the Senate, said Tuesday that the department had lied to Congress in its Feb. 4 letter and that Holder “did a lot of dodging and weaving” in his testimony on Tuesday.

Democrats defended Holder and suggested that he had helped put the controversy behind him.

“The American people should not lose sight of the big picture and the job the Justice Department is doing to keep us safe and secure,” Leahy said, citing the recent disruption of an alleged Iranian plot to kill the Saudi ambassador to Washington and last week’s charges against four Georgia men accused of scheming to carry out an attack with explosives and a deadly toxin.

Sen. Charles E. Schumer (D-N.Y.) tried to turn the blame to Republicans, pointing to recent revelations that gun walking was used in a George W. Bush administration initiative, also based in Phoenix, known as “Operation Wide Receiver.” The tactics in that operation were outlined in a 2007 briefing prepared for then-Attorney General Michael Mukasey.

“There’s been a selective way in which this investigation has been pursued,” Schumer said.

Holder defended his tenure, citing the department’s counter-terrorism efforts, financial fraud cases and a record number of criminal civil rights prosecutions. “I am proud of these — and our many other — achievements. And I am committed to building on this progress,” he said.

Even as he called the tactics used in Fast and Furious “unacceptable,” Holder struck back against his critics, condemning what he called “headline-grabbing Washington ‘gotcha’ games and cynical, political point-scoring.” His voice growing animated at times, he called on congressional Republicans to pass tougher gun laws and criticized what he called “overheated rhetoric,” suggesting that Fast and Furious “was somehow the cause of the epidemic of gun violence in Mexico.”

The attorney general came under fire Tuesday from Sen. John Cornyn (R-Tex.) over the death in December of U.S. Border Patrol Agent Brian Terry, who was killed during a firefight in the Arizona desert with five suspected illegal immigrants.

The serial numbers on two AK-47 semiautomatic rifles found near the scene matched those on guns bought outside Phoenix by a Fast and Furious suspect, although neither of the firearms could be definitively linked to Terry’s killing.

“Have you apologized to the family of Brian Terry?” Cornyn asked Holder, interrupting his answers at times.

Holder said he had not, nor had he spoken to family members.

“I certainly regret what happened to Agent Terry. I can only imagine the pain that his family has had to deal with,” Holder said, before adding: “It’s not fair, however, to assume that the mistakes that happened in Fast and Furious directly led to the death of Agent Terry.”