President Obama's CIA director on Friday urged agency employees to concentrate on their mission and not get sidetracked by the high-volume argument in Washington spurred a day earlier when House Speaker Nancy Pelosi accused the CIA of lying to Congress.

"There is a long tradition in Washington of making political hay out of our business. It predates my service with this great institution, and it will be around long after I'm gone. But the political debates about interrogation reached a new decibel level yesterday when the CIA was accused of misleading Congress," CIA Director Leon Panetta wrote in a letter publicly released.

"My advice -- indeed, my direction -- to you is straightforward: ignore the noise and stay focused on your mission. We have too much work to do to be distracted from our job of protecting this country," he wrote. "We are an agency of high integrity, professionalism, and dedication. Our task is to tell it like it is-even if that's not what people always want to hear. Keep it up. Our national security depends on it."

Panetta's letter was released as the debate grew over what Pelosi knew, when she knew it and whether she complained about it if she was so bothered by it. 

Pelosi told reporters on Thursday that those briefing her in September 2002 gave her inaccurate and incomplete information. Pelosi's office issued a statement Thursday saying Pelosi had been told in September 2002 that waterboarding, or simulated drowning, had not been used, but was going to be used in the future.

On Friday, Pelosi issued a statement and said criticism of the manner in which the Bush administration did not appropriately inform Congress is separate from her respect for those in the intelligence community.

"What is important now is to be united in our commitment to ensuring the security of our country; that, and how Congress exercises its oversight responsibilities, will continue to be my focus as we move forward," said Pelosi.

The timeline is the basis for the speaker's claim that the CIA lied to Congress -- because the CIA has confirmed later that it used waterboarding on Abu Zubaydah in August 2002.

Panetta repeated in his letter to CIA staff that the agency's response to congressional inquiries show that "our contemporaneous records from September 2002 indicate that CIA officers briefed truthfully on the interrogation of Abu Zubaydah, describing 'the enhanced techniques that had been employed.' Ultimately, it is up to Congress to evaluate all the evidence and reach its own conclusions about what happened."

The White House refused to be drawn into the debate Friday, with White House spokesman Robert Gibbs declining to weigh in on whether the CIA lied to Pelosi. 

"I appreciate the invitation to get involved, but I'm not going to RSVP," Gibbs said.

At the time of the briefing, Pelosi did not issue a complaint about possible future use of waterboarding. She said she was told five months later that waterboarding had been used. 

She said at that time, in February 2003, her concerns about the enhanced interrogation techniques were voiced in a letter written by California Rep. Jane Harman, who was the House Intelligence Committee ranking Democrat. 

But the Feb. 10, 2003, letter outlined Harman's concerns over policy, not concerns over the legality of the program. In the letter, Harman wrote to CIA General Counsel Scott Muller asking whether President Bush had authorized and approved the enhanced techniques because of the impact such methods may have on policy.

"What was described raises profound policy questions and I am concerned about whether these have been as rigorously examined as the legal questions," Harman wrote, according to a redacted copy of the letter released on Jan. 3, 2008. 

"I would like to know what kind of policy review took place and what questions were examined.  In particular, I would like to know whether the most senior levels of the White House have determined that these practices are consistent with the principles and policies of the United States.  Have enhanced techniques been authorized and approved by the president?"  

Harman also stated that she wanted videotapes of the interrogation of terror leader Abu Zubaydah to be preserved to serve as "the best proof that the written record is accurate, if such record is called into question in the future." In her statement of Jan. 3, 2008, Harman said her concern about the videotapes was her reason for releasing the letter.

Harman wrote that she was assured by intelligence officials at a Feb. 5, 2001, briefing she attended with then-Intelligence Committee Chairman Porter Goss that certain methods had been approved by the attorney general and subjected "to an extensive review by lawyers at the Central Intelligence Agency, the Department of Justice and the National Security Council and found to be within the law."

Harman went on to say that she appreciated the "difficult challenges" the CIA faced after Sept. 11, 2001, and that she knew that "the balance between security and liberty must be constantly evaluated and recalibrated in order to protect our nation and its people from catastrophic terrorist attack."

"I thus appreciate the obvious effort that you and your office have made to address the tough questions," Harman wrote. 

On Feb. 28, 2003, Muller wrote back to Harman, saying that "a number of executive branch lawyers including lawyers from the Department of Justice participated in the determination that, in the appropriate circumstances, use of these techniques is fully consistent with U.S. law.  While I do not think it appropriate for me to comment on issues that are a matter of policy, much less the nature and extent of executive branch policy deliberations, I think it would be fair to assume that policy as well as legal matters have been addressed within the executive branch."

At a press conference on Thursday, Pelosi told reporters that she supported the letter Harman drafted for Muller that raised concerns over the legality of the program.

Pelosi said her staffer told her in February 2003 that Harman and Goss "had been briefed about the use of certain techniques which had been the subject of earlier legal opinions. Following that briefing, a letter raising concerns was sent to CIA general counsel, Scott Muller, by the new Democratic ranking member of committee, the appropriate person to register a protest," Pelosi said

"But no letter or anything else is going to stop them from doing what they're going to do," she added.

Click here to read the Harman and Muller letters.

FOX News' Jim Angle contributed to this report.