WASHINGTON (CNN) -- The White House and Justice Department say what looks like a contradiction between testimony of Attorney General Alberto Gonzales and FBI Director Robert Mueller is nothing more than a confusion of terms.
Attorney General Alberto Gonzales testifies under oath Tuesday before the Senate Judiciary Committee.
White House spokesman Tony Snow said Friday that Gonzales "has testified truthfully and tried to be very accurate" when discussing a controversial surveillance program.
But when publicly discussing "matters of classification," Snow said, "Sometimes it's going to lead people to talk very carefully and there's going to be plenty room for interpretation or conclusion."
In a statement Thursday night, Brian Roehrkasse, acting Justice Department public affairs director, wrote, "Confusion is inevitable when complicated classified activities are discussed in a public forum."
Mueller told Congress on Thursday that a 2004 discussion between Gonzales, then White House counsel, and then-Attorney General John Ashcroft in Ashcroft's hospital room concerned the surveillance program. Gonzales had told a Senate panel on Tuesday that the program wasn't the subject of the conversation.
Mueller said he spoke with Ashcroft soon after Gonzales left the hospital and was told the meeting dealt with "an NSA [National Security Agency] program that has been much discussed, yes."
The apparent contradiction further fueled calls for the embattled Gonzales to resign. Mueller's testimony came hours after four Democratic members of the Senate Judiciary Committee requested that Solicitor General Paul Clement appoint a special counsel to investigate whether Gonzales perjured himself in his testimony.
Snow said that members of Congress were trying to "create controversies." Watch Snow's response to Democratic charges »
"Does Bob Mueller once use the phrase 'terrorist surveillance program'?" Snow asked. "The answer is no. He talks about 'an NSA program.'
"It's exactly what I'm talking about, which is that members of Congress are trying to create controversies about highly classified matters, some of which cannot, should not and must not be discussed publicly," Snow said.
"And it forces people to give very careful answers that could very easily be twisted by folks on the other side of the aisle."
At issue is the terrorist surveillance program, which allowed security officials to eavesdrop without a warrant on phone calls into or out of the United States in which one of the parties is a suspected terrorist.
Former U.S. Rep. Bob Barr of Georgia, a former U.S. attorney, said that there is "no conclusion other than the fact that they're talking about the same thing."
"There aren't many programs like this that have been 'much discussed' like this lately," Barr said.
In testimony Tuesday before the Senate Judiciary Committee, Gonzales, now attorney general, said he had visited the ailing Ashcroft in the hospital to discuss "other intelligence activities," not the surveillance program.
Mueller also testified Thursday that he had serious reservations about the program, which allowed surveillance without warrants, at the time of the dramatic internal administration showdown and threats of top-level resignations.
Mueller did not confirm he had threatened to resign, but he twice said he supported the testimony of former Deputy Attorney General James Comey, who testified that Gonzales and former White House Chief of Staff Andrew Card tried to pressure Ashcroft to reauthorize the surveillance program against terror suspects.
Mueller for the first time publicly confirmed he dispatched -- as Comey testified -- an FBI security detail to Ashcroft's hospital room to ensure that Comey was not removed from the room when Gonzales was there.
Clement, the solicitor general, was called on to look at appointing a special prosecutor because both Gonzales and Deputy Attorney General Paul McNulty have recused themselves from the matter.
President Bush appointed Clement to his post in 2005.
In announcing the request for a special counsel Thursday, Sen. Chuck Schumer, D-New York, said, "The attorney general took an oath to tell the truth, the whole truth and nothing but the truth. Instead he tells the half-truth, the partial truth and everything but the truth -- and he does it not once, not twice, but over and over and over again."
In addition to Schumer, Sens. Dianne Feinstein of California, Sheldon Whitehouse of Rhode Island and Russ Feingold of Wisconsin signed the letter.
Sen. Arlen Specter of Pennsylvania, the ranking Republican on the Senate Judiciary Committee and a Gonzales critic, said he doesn't support Schumer's request for a special counsel.
Specter accused the senators who signed the letter of moving too quickly on allegations that are "very, very serious," without consulting the rest of the panel. He noted that Judiciary Committee Chairman Sen. Patrick Leahy, a Vermont Democrat, had not signed the letter.
"I think the fact that he [Leahy] has not signed it is highly significant," Specter said. "I don't think you rush off and ask for appointment of a special counsel to run that kind of an investigation."
CNN senior legal analyst Jeffrey Toobin, a former assistant U.S. attorney, said there is a "realistic possibility" that Gonzales could come under criminal investigation, but he pointed out, "The one thing Gonzales may have going for him in this whole controversy is that because these matters are so highly classified, what exactly they're talking about may not have been precisely clear." E-mail to a friend
CNN's Kevin Bohn and Terry Frieden contributed to this report.