But Bush said he is confident that the recent spate of resistance is only temporary and does not reflect the feelings of average Iraqis. He laid the blame on former loyalists of deposed President Saddam Hussein, fighters from other countries, and adherents of outspokenly anti-coalition Shi'a cleric Muqtada al-Sadr.
"The violence we have seen is a power grab by these extreme and ruthless elements. It's not a civil war, it's not a popular uprising. Most of Iraq is relatively stable. Most Iraqis by far reject violence and oppose dictatorship," Bush said.
So far this month, 83 U.S. military personnel have been killed in Iraq and 560 have been wounded, more than in any other full month since Hussein was ousted last April. Since the war began 13 months ago, 678 U.S. soldiers have died.
The violence has taken a political toll on Bush with just seven months before he faces re-election, according to most public-opinion polls. The president's approval rating on national security is just above 50 percent. Overall -- on issues ranging from security to the economy -- fewer than 50 percent of Americans questioned in the surveys believe he is doing a good job.
It was a low approval rating that led President Lyndon Johnson not to seek re-election in 1968, at the height of the Vietnam War. But Bush said he is ready to face the judgment of the American voters, and spoke resentfully about some critics' comparison of Iraq with Vietnam. "I think the analogy is false," he said. "I also happen to think that analogy is -- sends the wrong message to our troops, and sends the wrong message to the enemy. Look, this is hard work. It's hard to advance freedom in a country that has been strangled by tyranny. And yet we must stay the course because the end result is in our nation's interest."
Bush also said he would not postpone the planned handover of sovereignty to Iraqis on 30 June. He said Washington would immediately recognize the new Iraq government, open an embassy in Baghdad, and appoint an ambassador.
Asked exactly what form of government would take power on 30 June, Bush said that was being arranged by Lakhdar Brahimi, the special United Nations envoy to Baghdad. He said he expected an answer soon.
Meanwhile, Bush said, U.S. aid to Iraq will continue, and U.S. forces will continue to provide security. He promised not to ease the military effort in Iraq, which he called just one front in a larger war against militant groups like Al-Qaeda, which he blames for the attacks in the United States on 11 September 2001.
"Over the last several decades, we've seen that any concession or retreat on our part will only embolden this enemy and invite more bloodshed. And the enemy has seen over the last 31 months that we will no longer live in denial or seek to appease them. For the first time the civilized world has provided a concerted response to the ideology of terror with a series of powerful, effective blows," Bush said.
He said these blows had not only driven the Taliban from power in Afghanistan and scattered Al-Qaeda; not only deposed Saddam Hussein, who now awaits trial; but even served to persuade Muammar Gaddhafi of Libya to give up his unconventional weapons. Bush cited the recent discovery of 50 tons of mustard gas that Gaddhafi's government had been hiding on a turkey farm.
Bush also answered questions about his administration's preparedness in the days before the 11 September attacks. Recent hearings by a special commission indicate that the Federal Bureau of Investigation (FBI) may not have been as alert to threats from Al-Qaeda as previously believed.
The White House has long said the president and his closest aides were doing as much as they could to protect Americans, given the information they were provided. But one recently declassified intelligence briefing that the president received about a month before the 11 September attacks seemed to indicate that Al-Qaeda was plotting an attack within the country. Bush said there was "nothing new" in that briefing. He said that, at most, the briefing merely confirmed what he already knew: Al-Qaeda hated the United States and was determined to attack eventually.
One questioner recalled the public apology offered three weeks ago by Bush's former chief counterterrorism aide, Richard Clarke. Appearing before the commission, Clarke said he did his best to thwart the attacks, but failed. Bush was asked if he, too, felt the need to apologize or take personal responsibility for the lapse. The president deflected both questions, saying only that he grieved with those who lost loved ones in the attacks, and that he wished government had been better coordinated to prevent the bloodshed.
Bush also was asked about critics who accused him of being incapable of admitting to mistakes. The reporter asked the president if he had made any mistakes since the 11 September attacks. The president hesitated for several seconds, made several false starts, then spoke of what he indicated were not mistakes, but accomplishments.
"I would have gone into Afghanistan the way we went into Afghanistan. Even knowing what I know today about the stockpiles of weapons [in Iraq], I still would have called upon the world to deal with Saddam Hussein. See, I happen to believe that we'll find out the truth on the weapons. That's why we set up the independent [weapons-search] commission. I look forward hearing the truth, just exactly where they are. They could still be there. They could be hidden like the 50 tons of mustard gas on a turkey farm," Bush said.
Finally, Bush told his questioner that he was certain he had made some mistakes, but he simply couldn't think of any amid the pressure of a news conference.