Cheney said Clarke "may have had a grudge to bear" and suggested that he had left the White House after being passed over for a promotion.
On the eve of public hearings by the federal panel reviewing the Sept. 11 attacks, Cheney and other top administration officials sought to counter accusations by Clarke that Bush was so preoccupied with Iraq both before and after those attacks that he failed to effectively confront threats from the al-Qaida terrorist network.
Cheney, in an interview with radio talk-show host Rush Limbaugh, said Clarke "clearly missed a lot of what was going on" during the two years he worked at the Bush White House.
National Security Adviser Condoleezza Rice said on CNN, "I really don't know what Richard Clarke's motivations are, but I'll tell you this: Richard Clarke had plenty of opportunities to tell us in the administration that he thought the war on terrorism was moving in the wrong direction, and he chose not to."
And the president's press secretary, Scott McClellan, told a White House briefing: "His assertion that there was something we could have done to prevent the Sept. 11 attacks from happening is deeply irresponsible. It's offensive and it's flat-out false."
Clarke resigned his White House job 13 months ago, after having held senior posts under Presidents Reagan and Clinton and the first President Bush.
In his book, "Against All Enemies," Clarke wrote that the current president "launched an unnecessary and costly war in Iraq that strengthened the fundamentalist, radical Islamic terrorist movement worldwide."
Cheney said of Clarke's assertions, "I fundamentally disagree with his assessment both of recent history, but also in terms of how to deal with the problem" of global terrorism.
The White House took issue with a conversation Clarke reported that he and several other aides had with Bush in the White House Situation Room on Sept. 12, 2001, the day after the attacks.
"See if Saddam did this," Bush is quoted by Clarke as saying.
McClellan said Bush "doesn't have any recollection" of such a meeting or conversation.
Furthermore, McClellan said, "There's no record of the president being in the Situation Room on that day ... you know, when the president is in the Situation Room, we keep track of that."
McClellan sought to tie the book to Democratic Sen. John Kerry's presidential campaign by saying that Clarke's "best buddy" is Rand Beers, who resigned as a top counterterrorism official at the National Security Council after the invasion of Iraq and later became Kerry's national-security and homeland-security issues coordinator.
Clarke says he is a registered Republican.
"It's important to keep in context we're in the heat of a presidential campaign and all of a sudden he comes out with a book that he is seeking to promote ... and he is making charges that simply did not happen," McClellan said.
"This is Dick Clarke's American grandstand. He just keeps changing the tune," McClellan added.
Although some Republican leaders defended the White House and joined in denouncing Clarke, others expressed concern that the former aide's accusations would compound a recent fall in Americans' perception of Bush's honesty that began with the flawed charges about Iraq's weapons of mass destruction.
Sen. Chuck Hagel, R-Neb., said he believes the White House has to respond directly to Clarke's allegations rather than question his credibility. "This is a serious book written by a serious professional who's made serious charges, and the White House must respond to these charges," he said.