Updated

President Bush said Thursday he opposes establishing a special commission to probe how the government dealt with terror warnings before Sept. 11, saying the matter should be dealt with by congressional intelligence committees.

Bush said the investigation should be confined to Congress because it deals with sensitive information that could reveal sources and methods of intelligence. Therefore, he said, the congressional investigation is ``the best place'' to probe the events leading up to the terrorist attacks.

The president spoke at a joint news conference with German Chancellor Gerhard Schroeder on the first stop of a four-nation European trip.

Bush said he retains ``great confidence'' in the CIA and FBI despite revelations about advance intelligence that terrorists might hijack an airplane. Bush himself received a memo in August that mentioned the possibility of an airline hijacking.

While some in Congress have called for the release of that memo, Bush said information given to the president must be protected ``because we don't want to give away sources and uses and methodology of intelligence gathering.''

``We're still at war. We've got threats to the homeland,'' Bush said. He said it is important not to impede the ability to wage war against terror.

Bush's remarks came a day after Vice President Dick Cheney said a new series of public terror warnings was based on increased threats and was not a political strategy to deflect criticism of the administration's handling of pre-Sept. 11 intelligence.

``The fact is there is reason to believe that the threat level has increased somewhat,'' Cheney said Wednesday on CNN's ``Larry King Live.'' ``We see more noise in the system, more reporting that leads us to be cautious here. We haven't changed our practices at all in terms of when we decide to go public and caution people.''

Authorities continued to tighten security around New York City landmarks after the FBI disclosed uncorroborated information from detainees that sites such as the Statue of Liberty and Brooklyn Bridge might be attacked.

Cheney said the White House was not raising the nationwide terrorism alert status — currently at yellow, the third-highest of five levels — because intelligence on possible attacks was too vague.

Cheney also said a special, independent commission into how the government dealt with terror warnings before Sept. 11 would result in intelligence leaks. Democrats, including Senate Majority Leader Tom Daschle, D-S.D., have proposed that a special commission investigate the matter and have suggested that more should have been done with the advance intelligence.

Congress is already investigating.

``Our concern is that if we lay another investigation on top of that we'll just multiply potential sources of leaks and disclosures of information we can't disclose,'' Cheney said. ``The key to our ability to defend ourselves and to take out the terrorists lies in intelligence.''

Daschle questioned the Bush administration's motive for resisting the commission.

``I think while we respect the need for secrecy, we also have a strong belief in the need for sharing information so that we can make good judgments about the facts,'' Daschle said in a speech at the National Press Club. ``And there is an increasing pattern that I find in this administration that reflects an unwillingness to share information — not only with us but within their own administration; one department not telling the other, people in positions of responsibility not telling the president.''

The political battle intensified Wednesday over what information the government had before Sept. 11 about possible terror attacks. For the second day, FBI Director Robert Mueller and agent Kenneth Williams testified behind closed doors to lawmakers investigating what the government knew.

Williams wrote a pre-Sept. 11 warning about Arab students at an Arizona flight school that he hoped would lead to screenings of Middle Easterners who came to study U.S. airport operations, according to government officials familiar with his account.

Williams' July 10, 2001, memo linked the Arab students to a militant Muslim group in London whose leader openly supported Osama bin Laden, said government officials, speaking on condition of anonymity.

On Tuesday, both Mueller and Williams gave testimony to the Senate Judiciary Committee. They appeared before the House and Senate Intelligence committees Wednesday.

Sen. Richard Shelby, R-Ala., vice chairman of the Senate Intelligence Committee, called the memo ``highly embarrassing to the bureau'' and called for its public release after the briefing.

He said Williams, as well as those agents investigating Zacarias Moussaoui in Minnesota, had sniffed out aspects of the plot — ``they were on the ball'' — but their warnings went unheard by higher-ups.

``I believe there's a lot of blame to go around, but, as we get into in our inquiry, we will find more and more about it,'' Shelby said. ``I'm not satisfied with the response by the FBI today or their performance.''

As the debate over the commission continued, the Bush administration sought to qualify the threats that the United States faces from terrorists after a week of warnings from Bush, Defense Secretary Donald H. Rumsfeld and Secretary of State Colin Powell.

Rumsfeld said Wednesday his comment the day before that terrorists would inevitably gain weapons of mass destruction was not based on new information.

``The words were the same, the language was the same, the import was the same as I have been saying for months,'' Rumsfeld said.