Washington, DC - President Bush accepted responsibility yesterday for making an allegation about Saddam Hussein's nuclear ambitions that was based on flawed intelligence, but he broadly defended the war against Iraq and the evidence his administration used to justify the conflict.

The president's taking of "personal responsibility" for the charge in his State of the Union address that Iraq sought nuclear material in Africa followed three weeks in which he allowed others on his staff and at the CIA to take the blame for including the charge, which was doubted by U.S. intelligence and was later learned to be based in part on forged documents.

Bush's acknowledgment was part of a lengthy and wide-ranging news conference in the Rose Garden assessing developments abroad and at home in the first half of the year on the eve of the president's month-long break at his Texas ranch.

On other subjects, Bush vowed no compromise in his opposition to gay marriage and said administration lawyers are working on a way to raise federal obstacles to same-sex marriage. He repeated his rebuff to Saudi officials who want the administration to make public a report accusing Saudi Arabia of helping the Sept. 11, 2001, attackers, and he said he still believes a Middle East peace deal can be reached in two years.

The president, in high spirits and often playful with his questioners, expressed unwavering confidence about succeeding in the full range of challenges facing his administration and the country. Despite a government warning of a renewed terrorist threat to air travel, Bush said, "I'm confident we will thwart the attempts."

He also said he is confident that links will be proved between ousted Iraqi President Saddam Hussein and al Qaeda, that Hussein and his loyalists will be found and defeated, that his trio of tax cuts will give the economy the boost it needs and that progress is being made against Iranian and North Korean nuclear weapons programs.

Still, Bush was less expansive in his claims than he was 90 days earlier, when he declared an end to major combat in Iraq while standing on an aircraft carrier beneath a banner proclaiming "Mission Accomplished." Yesterday, the president said "the United States and our allies will complete our mission in Iraq" as he discussed the continued threat to U.S. troops in Iraq, 50 of whom have been killed in hostilities in 90 days.

The president did not promise that weapons of mass destruction will be found in Iraq. Bush had earlier said with certainty that such weapons would be found but spoke instead yesterday of a "weapons program" rather than actual weapons. "I'm confident that our search will yield that which I strongly believe, that Saddam had a weapons program," he said. Aides played down the distinction when Bush first made the switch a few weeks ago, but the change has since become standard.

"Look, in my line of work, it's always best to produce results, and I understand that," Bush said during the 52-minute news conference in the summer sun. The session was called on 90 minutes' notice as Bush prepared to leave Saturday for a month-long vacation at his ranch in Crawford, Tex., and half a dozen fundraisers for his reelection effort. "In order to, you know, placate the critics and the cynics about intentions of the United States, we need to produce evidence," he said.

Bush's aides have been struggling since July 7 to explain why he declared in his Jan. 28 address to Congress that Hussein "recently sought significant quantities of uranium from Africa" despite earlier CIA warnings to avoid the claim. Bush since then had deflected questions about whether he took responsibility for the claim, which administration officials have alternately described as wrong and unsubstantiated.

The president amended his answer yesterday. "I take personal responsibility for everything I say, of course," Bush said. He then shifted to the broader defense of the war he had previously made. "I also take responsibility for making decisions on war and peace," he said. "I analyzed a thorough body of intelligence, good, solid, sound intelligence that led me to come to the conclusion that it was necessary to remove Saddam Hussein from power."

Bush strongly endorsed national security adviser Condoleezza Rice, whose public statements about the nuclear threat posed by Hussein had been contradicted by other officials and emerging facts. "Dr. Condoleezza Rice is an honest, fabulous person, and America is lucky to have her service -- period," Bush said, rapping the podium for emphasis.

Rice, last night on PBS' "The NewsHour," also shouldered blame for the first time. "I certainly feel personal responsibility for this entire episode," she said. "The president of the United States has every right to believe that what he is saying in his speeches is of the highest confidence of his staff . . . . In this one case, the process did not work."

Bush and his aides had never concealed his distaste for formal news conferences. Bush's eight news conferences to date compare with 33 by Bill Clinton and 61 by George H.W. Bush at similar times in their presidencies, according to a tally by the Associated Press. But Bush seemed to be enjoying himself yesterday.

He joked that his advancing age prevented him from remembering multipart questions, and made mirth of his stumble over the name of a captured terrorist. Bush called him "Ramzi -- Ramzi al Shibh, or whatever the guy's name was," to laughter from the press corps. "Sorry, Ramzi, if I got it wrong." Then it came to him: "Binalshibh -- excuse me."

When a CBS News correspondent attempted a follow-up question on the sensitive subject of the Iraq weapons intelligence, Bush dispatched the questioner by saying, "I'm kind of finding my feet." When the correspondent tried again, Bush cut him off with a curt "you're through." Discussing "frustration" in the media about a lack of results in Iraq, Bush said in an aside to an NBC News correspondent: "You don't look frustrated to me at all."

Bush exhibited his trademark folksiness, stating five times that "we're on the hunt" for Hussein and terrorists and referring to one dead terrorist by the nickname "Swift Sword." Interrupting a question about how he could spend the $ 170 million or more that he will raise for his reelection in his unopposed primary campaign, Bush exclaimed: "Just watch!" Bush, who is holding 15 fundraisers this summer, was unabashed in saying the fundraising is an "early barometer" of success.

On gay marriage, Bush stopped short of endorsing a constitutional ban that is being championed by some Republican leaders. But he left open the possibility of supporting such an amendment, which may be the only way Washington could expand on the 1996 Defense of Marriage Act, which denies federal recognition to same-sex marriages and allows states to ignore same-sex unions performed elsewhere.

An administration official said White House lawyers "are looking at what may be needed legally to protect the sanctity of marriage." Another senior aide said the White House is seeking to determine if a constitutional ban is "the only way to go."

Asked for his "view on homosexuality," Bush replied, "I am mindful that we're all sinners, and I caution those who may try to take the speck out of their neighbor's eye when they've got a log in their own." But, he continued: "That does not mean that somebody like me needs to compromise on issues such as marriage. . . . I believe a marriage is between a man and a woman. And I think we ought to codify that one way or the other."

The remarks infuriated gay rights supporters. Rep. Janice D. Schakowsky (D-Ill.) said in a letter to Bush that she was "shocked and insulted" that he "seemed to equate homosexuality with sin." But Republican lawmakers believe the gay marriage ban is a winning issue. Although Americans favor tolerance of homosexuality, they say, a majority of the public opposes government-sanctioned gay marriage.

On the Middle East, Bush said he thinks the goal of a Palestinian state by 2005, set in the administration-backed "road map" to peace, remains "realistic," despite the view of many experts that it is unattainable given the current pace of negotiations. He volunteered generous praise for Palestinian Prime Minister Mahmoud Abbas.

Much of the news conference dealt with various aspects of the war on terrorism, including a federal warning on Saturday to airlines that terrorists might be working in five-man teams to seize commercial aircraft later this summer. "The threat is a real threat," Bush said. But he expressed confidence that the government will defuse the threat.

Bush was upbeat in discussing nuclear proliferation in the two other members of his "axis of evil," which included Iraq. He said that "we're actually beginning to make serious progress" getting Asian nations to share responsibility for dealing with North Korea and its nuclear ambitions "in such a way that I believe will lead to an attitudinal change by Kim Jong Il." Bush also said he is "pleased by the attitudes" of Europeans joining in recognizing the threat of a nuclear-armed Iran.

The president was similarly upbeat on domestic matters. He spoke of "hopeful signs" on the economy and said only a quarter of the budget deficit, now estimated by the White House at $ 455 billion this year and more next year, comes from tax cuts. Bush said another quarter comes from "additional spending on the war on terror" and half from "lack of revenues."