WASHINGTON, Feb. 20 — The Central Intelligence Agency has acknowledged that it did not provide the United Nations with information about 21 of the 105 sites in Iraq singled out by American intelligence before the war as the most highly suspected of housing illicit weapons.
The acknowledgment, in a Jan. 20 letter to Senator Carl Levin, Democrat of Michigan, contradicts public statements before the war by top Bush administration officials.
Both George J. Tenet, the director of central intelligence, and Condoleezza Rice, the national security adviser, said the United States had briefed United Nations inspectors on all of the sites identified as "high value and moderate value" in the weapons hunt.
The contradiction is significant because Congressional opponents of the war were arguing a year ago that the United Nations inspectors should be given more time to complete their search before the United States and its allies began the invasion. The White House, bolstered by Mr. Tenet, insisted that it was fully cooperating with the inspectors, and at daily briefings the White House issued assurances that the administration was providing the inspectors with the best information possible.
In a telephone interview on Friday, Senator Levin said he now believed that Mr. Tenet had misled Congress, which he described as "totally unacceptable."
Senior administration officials said Friday night that Ms. Rice had relied on information provided by intelligence agencies when she assured Senator Levin, in a letter on March 6, 2003, that "United Nations inspectors have been briefed on every high or medium priority weapons of mass destruction, missile and U.A.V.-related site the U.S. intelligence community has identified." Mr. Tenet said much the same thing in testimony on Feb. 12, 2003.
U.A.V.'s are unmanned aerial vehicles, commonly called drones.
Asked about the contradiction between the C.I.A.'s current account and Ms. Rice's letter, the spokesman for the national security council, Sean McCormack, said, "Dr. Rice provided a good-faith answer to Senator Levin based on the best information that was made available to her."
This is not the first time the White House and the C.I.A. have engaged in finger-pointing about the quality of the intelligence that formed the basis of administration statements.
Last summer, Dr. Rice noted that Mr. Tenet had not read over the State of the Union address in which Mr. Bush said Saddam Hussein had attempted to buy uranium from Africa, a statement the White House later acknowledged was based on faulty intelligence. That began a prolonged period of tension between the agency and the White House that has never fully abated, and may be inflamed by the C.I.A.'s acknowledgment to Senator Levin.
The letter to Senator Levin, from Stanley M. Moskowitz, the agency's director of Congressional affairs, disclosed that the agency had shared information on only 84 of the 105 suspected priority weapons sites.
Mr. Moskowitz did not directly account for the sites omitted. But he cited an earlier letter from the agency to the senator that said the agency had sought to help the United Nations by providing "the intelligence that we judged would be fruitful in their search for prohibited material and activities in Iraq."
In a letter to Senator Levin on May 23, 2003, Mr. Tenet had also said that "in hindsight, we could have been more precise in the words we chose to describe which of the high and medium sites that we gave" to United Nations inspectors.
Mr. Tenet added in that letter, "We were focusing on the intelligence we had that we believed would lead to fruitful efforts by the inspectors, rather than trying to specifically decipher our `list of lists' and the process by which we shared information."
An intelligence official who spoke on condition of anonymity described Senator Levin as "obsessed with this particular issue" and said the C.I.A. had done nothing inappropriate. "We provided the best information that we had, and the notion that we held back information that would have been useful is just absurd," the official said.
Mr. Moskowitz suggested that the sites about which the C.I.A. had not provided information were already known to United Nations inspectors.
The acknowledgment by the agency came after more than a year of questions from Senator Levin. He said he believed that the Bush administration had withheld the information because it wanted to persuade the American people that the United Nations-led hunt for weapons in Iraq had run its full course before the war.