Bin Ladin, taunting the man who has vowed to take him "dead or alive" for the past three years, said Bush had failed Americans with his Middle East policies, deceiving the nation and provoking Muslim groups like al-Qaida to strike again.
Looking healthy and defiant in a video released from hiding to Aljazeera just four days before the US presidential poll, Bin Ladin accused Bush of complacency during the September 11 attacks in 2001, mocking him for going on with a visit to a school.
"Despite entering the fourth year after September 11, Bush is still deceiving you and hiding the truth from you and therefore the reasons are still there to repeat what happened," he said, making his clearest claim yet of responsibility.
In what seemed a deliberate attempt to influence Tuesday's US election, bin Ladin used the opening line: "O American people, I am speaking to tell you about the ideal way to avoid another Manhattan, about war and its causes and results."
But he made little mention of Bush's Democratic challenger John Kerry, saying: "Your security is not in the hands of Kerry or Bush or al-Qaida. Your security is in your own hands and each state which does not harm our security will remain safe."
Bush, who ordered US forces to capture Bin Ladin dead or alive after the September 11 attacks, vowed that "Americans will not be intimidated or influenced by an enemy of our country" and said "we will prevail" in the so-called "war on terror".
A US Department of State official said Washington had asked the government of Qatar, where Aljazeera is based, to prevent the station from airing the latest Bin Ladin tape.
Kerry, Bush response
Kerry, who has criticised Bush for failing to capture Bin Ladin by diverting troops to Iraq, called him "a barbarian".
"I will stop at absolutely nothing to hunt down and capture or kill the terrorists wherever they are, whatever it takes," he said. Kerry is currently running neck and neck with Bush in the opinion polls.
The Bush administration tried to
stop the tape being aired
After vowing to hunt down and kill terrorists, and noting that America was united in that desire, Kerry said: "I regret that when George Bush had the opportunity in Afghanistan at Tora Bora, he didn't use our sources to hunt down and kill Usama bin Ladin. He outsourced to the war lords."
Bush later said the Democrat's charge that bad strategy let the al-Qaida leader escape US forces in late 2001 was "especially shameful".
"Unfortunately my opponent tonight continued to say things he knows are not true, accusing our military of passing up a chance to get Usama bin Ladin at Tora Bora," an Afghan stronghold in 2001.
"As the commander in charge of that operation, [retired general] Tommy Franks has said: It's simply not the case," Bush said. "It is especially shameful in the light of a new tape from America's enemy."
Bin Ladin, speaking forcefully and jabbing his finger, said he thought of the idea of attacking the US skyscrapers when he saw Israeli aircraft bombing tower blocks in Lebanon in 1982, during an invasion which he accused Washington of supporting.
"As I watched the destroyed towers in Lebanon, it occurred to me to punish the unjust the same way ... to destroy towers in America so that it can taste some of what we are tasting and to stop killing our children and women," said bin Ladin.
"It occurred to me to punish the unjust the same way ... to destroy towers in America so that it can taste some of what we are tasting"
Usama bin Ladin
"God knows that it had not occurred to our mind to attack the towers, but after our patience ran out and we saw the injustice and inflexibility of the American-Israeli alliance toward our people in Palestine and Lebanon, this came to my mind," he said.
Describing Bush's actions at the school on September 11, he said: "It never occurred to us that the commander in chief of the American forces would leave 50,000 citizens in the two towers to face those horrors alone at a time when they most needed him."
Bin Ladin said millions of tonnes of bombs and explosives fell on Iraqi children, under the order of George Bush, just for the sake of ousting an old agent and replacing him by a new agent to help plunder Iraqi oil wealth.
He said the September 11 attacks came in response to those injustices.
Bin Ladin said Bush's Middle East
policies have failed
The al-Qaida leader, apparently sitting or standing at a table against a neutral brown background, wore a white turban and white tunic under a light brown cloak. His full beard was a mixture of white and dark grey.
The White House said there was no change in the US terror alert level despite the video. A US official said the video did not appear to contain a specific threat.
US intelligence agencies believed it appeared to be Bin Ladin on the tape, US officials said.
Commenting on the tape, Edmond Garib, a professor of international relations at the American University in Washington said: "Bin Ladin did not submit the tape by coincidence.
"The object here is to influence the American elections and to send messages to the Americans, Arabs and Muslims."
Garib, speaking to Aljazeera, said Bin Ladin's wording might be understood in two ways.
"First, that Bin Ladin's attacks against Bush will push Americans to gather around Bush as they hate Bin Ladin, and will support Bush's position. Bin Ladin's target is to appear that he is a strong man who challenges the United States in the Arab and Islamic worlds. This will win him more money and followers."
"Bin Ladin's target is to appear that he is a strong man who challenges the United States in the Arab and Islamic worlds"
Edmond Garib, professor of international relations, American University in Washington
Garib added that the appearance of Bin Ladin "in sight and sound will remind people that Bush, who used to talk about him and vowed to capture him dead or alive, stopped to mention him lately".
"This will support Kerry's position," he added.
Saudi-born Bin Ladin, who is in his late 40s, last appeared in a video broadcast by Aljazeera in September 2003, showing him and his deputy Ayman al-Zawahri descending a mountainside calling for jihad and praising the September 11 hijackers.
In April, Arab television stations broadcast an audio tape purportedly from Bin Ladin offering a three-month truce to Europeans if they withdrew troops from Muslim nations. The deadline expired with no word from Bin Ladin.