President Bush said Usama bin Laden's mention of the Iraq war in his video message is a reminder of Al Qaeda's long-term objectives in Iraq and of the "dangerous world in which we live."

"Iraq is part of this war against extremists," Bush said, responding to the terrorist leader's message but never using his name. "If Al Qaeda bothers to mention Iraq, it's because they want to achieve their objectives in Iraq, which is to drive us out."

Bin Laden's video, part of which was broadcast by Al-Jazeera television, emerged just days before the sixth anniversary of the Sept. 11 attacks.

In a 30-minute speech addressed to Americans, bin Laden mocks the democratic system of government in the United States and lambastes the Bush administration for initiating the war in Iraq.

Click here to read the transcript of Usama bin Laden video (pdf).

Bush, attending a summit of Pacific Rim leaders in Sydney, Australia, said: "The tape is a reminder about the dangerous world in which we live, and it's a reminder that we must work together to protect our people against these extremists who murder the innocent in order to achieve their political objectives."

The president spoke during a photo opportunity with Japanese Prime Minister Shinzo Abe, referring to "a tape" and "the tape" and sometimes using awkward phrasing, apparently to avoid bin Laden's name.

The new bin Laden video released Friday makes no overt threats against the United States but boasts about the devastating impact the 2001 terror attacks had on the nation — both domestically and overseas.

The Homeland Security Department was continuing to analyze the video to see if it includes any coded messages, department spokesman Russ Knocke said. But the department has found no credible information of an imminent threat to the homeland.

The nation's threat level remains the same — elevated for the nation and high for the aviation sector.

"Our strategic threat assessment is that we are in a period of increased risk," Knocke said. "We continue to call for heightened vigilance by authorities at all levels as well as by the American public, and we remind everyone that if they see something, please say something."

In the speech, bin Laden refers to the attacks on New York and Washington several times, almost gloating about policy changes by the U.S. government in response.

"Nineteen young men were able — by the grace of Allah, the Most High — to change the direction of its compass," bin Laden says of the nation in a transcript of the video obtained by The Associated Press.

"Since the 11th, many of America's policies have come under the influence of the Mujahedeen," bin Laden says. "And as a result, the people discovered the truth about it; its reputation worsened, its prestige was broken globally and it was bled dry economically."

"Mujahedeen" is a term for Muslims fighting in a war or involved in any other struggle.

Counterterror and intelligence officials confirmed it was bin Laden on the tape, which they said appears to have been recently made. Bin Laden mentions the Aug. 6 anniversary of the World War II bombing of Hiroshima, and includes British Prime Minister Gordon Brown among leaders of the West with a "flagrant disregard for the intellects of human beings." Brown became prime minister June 27.

Several current and former government officials said bin Laden's speech may have been at least partially written by 28-year-old Adam Gadahn, an American charged with treason and supporting terrorism for serving as an Al Qaeda propagandist. Authorities believe Gadahn tries to recruit supporters through videos and messages posted on the Internet.

Bin Laden mocks the democratic system of government in the United States, calling the nation "unjust," the transcript shows. At one point, he jeers President Bush's alliance with Iraqi Prime Minister Nouri al-Maliki; at another he singles out Vice President Dick Cheney, former Defense Secretary Donald Rumsfeld and former Pentagon adviser Richard Perle as neoconservatives.