Washington ? President George W. Bush conceded Monday in a sometimes emotional, sometimes defiant farewell news conference that he’d made mistakes and had disappointments on Iraq and Hurricane Katrina policies, but said that history would prove that his decisions generally were correct.

“Not finding weapons of mass destruction (in Iraq) was a significant disappointment,” he said. He’d used the threat of such weapons as the key rationale for invading Iraq in 2003.

More than 4,225 Americans have died in the war, which has been unpopular for years and was a major reason for the Republicans’ crushing defeat in November’s elections.

Bush plans to continue reflecting on his years in office in a prime-time farewell address Thursday. The speech is expected to be about 10 to 15 minutes long, in front of a live audience in the White House East Room. He’ll speak to what the White House calls “courageous people” he’s met during his eight years in office. The White House has asked the major television networks to air the address. No other details were available Monday.

The address, press secretary Dana Perino said, “would be the last scheduled public event before the president-elect arrives at the North Portico on Inauguration Day,” Jan. 20.

She said the farewell address was a ritual dating to George Washington, though the live audience element would be new. She added that “this is not going to be a swan song.”

The White House said in an e-mail, “He will reflect on his time in office and the ways our country has changed these past eight years. He will also uphold the tradition of presidents using farewell addresses to look forward — by sharing his thoughts on the greatest challenges facing the country, and on what it will take to meet them.”

The president, who’s been reluctant to admit errors, did concede that “clearly, putting ‘Mission Accomplished’ on an aircraft carrier was a mistake.” On May 1, 2003, the president stood on the USS Abraham Lincoln under that banner and declared that “the United States and its allies have prevailed.”

He also said Monday that the Abu Ghraib prison in Iraq, where American officials abused prisoners, “was obviously a huge disappointment.”

Perhaps the most pivotal political moment of his presidency came in late 2005 in the aftermath of Katrina, which devastated New Orleans and other parts of the Gulf Coast.

Bush was somewhat contrite, but also defensive, on Monday discussing the government’s actions:

“Don’t tell me the federal response was slow when 30,000 people were pulled off roofs when the storm passed. … Could things have been done better? Absolutely.”

The president broke little ground on more recent events during the 50-minute question-and-answer session. Whether to request the second $350 billion part of October’s financial-bailout package is up to President-elect Barack Obama, he said.

“I don’t intend to make the request,” Bush said, “unless he specifically asks me to make it.”

About an hour after the news conference, Obama asked Bush to make the request, and the White House said that the president would do so. No other details were available.

A congressional vote on whether to bar the money now is anticipated. Since Obama has signaled that he wants more money going to help homeowners, approval is expected.

Bush also reiterated his view of the Israel-Palestinian conflict.

“I’m for a sustainable cease-fire,” he said, “and a definition of a sustainable cease-fire is that Hamas stops firing rockets into Israel.

“And there will not be a sustainable cease-fire if they continue firing rockets. I happen to believe the choice is Hamas’ to make.”

He had few words of wisdom for his successor, joking that those who claim that the presidency is the world’s loneliest job are mistaken.

“I have never felt isolated, and I don’t think he will,” Bush said. “I believe the phrase ‘burdens of the office’ is overstated.”

In fact, he said, at times, “We had fun.”