Usama bin Laden (search) appeared to soften his language toward Americans in a new videotape, saying that the United States would be safe from attack if it left the Muslim world alone.

"Your security is not in the hands of Kerry, Bush or Al Qaeda (search). Your security is in your own hands," bin Laden said, referring to the president and his Democratic challenger. "Any state that does not mess with our security, has naturally guaranteed its own security."

In what appeared to be conciliatory language, bin Laden said in a tape that aired Friday he wanted to explain why he ordered the airline hijackings that hit the World Trade Center (search) and the Pentagon so Americans would know how to act to prevent another attack.

"To the American people, my talk is to you about the best way to avoid another Manhattan," he said. "I tell you: Security is an important element of human life and free people do not give up their security."

Injecting himself into the presidential campaign more than a year after his last televised appearance and four days ahead of Election Day, bin Laden said the United States can avoid another Sept. 11-style attack if it stops threatening the security of Muslims.

In the portion of the tape that was broadcast, the Al Qaeda leader refrained from directly warning of new attacks, although he said "there are still reasons to repeat what happened."

Admitting for the first time that he ordered the Sept. 11 attacks, bin Laden said he did so because of injustices against the Lebanese and Palestinians by Israel and the United States.

After the video was aired, President Bush said that "Americans will not be intimidated" by bin Laden. Sen. John Kerry criticized Bush for failing to capture bin Laden earlier and said that "I can run a more effective war on terror."

In the video, bin Laden accused Bush of misleading Americans by saying the attack was carried out because Al Qaeda "hates freedom." The terrorist leader said his followers have left alone countries that do not threaten Muslims.

"We fought you because we are free ... and want to regain freedom for our nation. As you undermine our security we undermine yours," bin Laden said.

He said he was first inspired to attack the United States by the 1982 Israeli invasion of Lebanon in which towers and buildings in Beirut were destroyed in the siege of the capital.

"While I was looking at these destroyed towers in Lebanon, it sparked in my mind that the tyrant should be punished with the same and that we should destroy towers in America, so that it tastes what we taste and would be deterred from killing our children and women," he said.

"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.

Bin Laden suggested Bush was slow to react to the Sept. 11 attacks, giving the hijackers more time than they expected. At the time of the attacks, the president was listening to schoolchildren in Florida reading a book.

"It never occurred to us that the commander in chief of the American armed forces would leave 50,000 of his citizens in the two towers to face these horrors alone," he said, referring to the number of people who worked at the World Trade Center.

"It appeared to him [Bush] that a little girl's talk about her goat and its butting was more important than the planes and their butting of the skyscrapers. That gave us three times the required time to carry out the operations, thank God," he said.

Excluding the hijackers, the Sept. 11 attacks killed 2,749 people at the World Trade Center, 184 at the Pentagon and 40 in Pennsylvania.

In planning the attacks, bin Laden said he told Mohammed Atta, one of the hijackers, that the strikes had to be carried out "within 20 minutes before Bush and his administration noticed."

Bin Laden compared the Bush administration to repressive Arab regimes "in that half of them are ruled by the military and the other half are ruled by the sons of kings and presidents."

He said the resemblance became clear when Bush's father was president and visited Arab countries.

"He wound up being impressed by the royal and military regimes and envied them for staying decades in their positions and embezzling the nation's money with no supervision," bin Laden said.

"He passed on tyranny and oppression to his son, and they called it the Patriot Act, under the pretext of fighting terror. Bush the father did well in placing his sons as governors and did not forget to pass on the expertise in fraud from the leaders of the [Mideast] region to Florida to use it in critical moments."

The political impact of the tape could cut both ways. It bolsters Bush's argument that the world is a dangerous place and plays to his strength as commander in chief in fighting the war on terror, but it also underscores that his administration has failed to capture or kill America's No. 1 enemy more than three years after the terror attacks on New York and Washington.

It was the first footage in more than a year of the fugitive Al Qaeda leader, thought to be hiding in the mountains along the Pakistan-Afghanistan border. The video, broadcast on Al-Jazeera television, showed bin Laden with a long, gray beard, wearing traditional white robes, a turban and a golden cloak, standing behind a table with papers and in front of a plain, brown curtain.

His hands were steady and he appeared healthy.

The Bush administration said it believes the videotape is authentic and was made recently, noting that bin Laden referred to 1,000 U.S. military deaths in Iraq — which happened in early September.

White House press secretary Scott McClellan said the administration did not plan to raise the nation's threat level for now. The U.S. official said the 18-minute tape — which carries English subtitles, though not in the portion shown on Al-Jazeera — lacks an explicit threat and repeats well-worn themes.

Multiple sources told FOX News that the tape is authentic and that it was made recently.

The Arabic television channel Al-Jazeera said Saturday that the tape was dropped off at the gate of the station's office in an envelope on Friday at its offices in Islamabad, Pakistan. It aired only hours later.

"We received it in Pakistan. ... Somebody dropped it yesterday at the gate," Ahmad Muaffaq Zaidan, Al-Jazeera's Pakistan bureau chief, told The Associated Press. "The guard brought it to me along with other mail. It was in an envelope, I opened it and it was a big scoop."

Zaidan said he immediately transmitted the tape to Al-Jazeera's headquarters in the Gulf nation of Qatar.

Bin Laden and his top deputy, Egyptian surgeon Ayman al-Zawahri, are both believed to be hiding in the mountains that straddle the Afghan-Pakistan border, although there has been no hard evidence of their whereabouts for more than three years.

Zaidan said the fact the tape was received by the station in Pakistan did not necessarily mean that bin Laden and al-Zawahri were in the area.

"It is very difficult to judge," Zaidan said.

Pakistani Interior Minister Aftab Khan Sherpao said authorities have no information about who might have given Al-Jazeera the tape, but he stuck to Pakistan's position that there was no proof bin Laden is in the country.

"We have no idea where they got it," he told AP. "I don't think he is in Pakistan."

Maj. Gen. Shaukat Sultan, the army spokesman, also said he doubted bin Laden was in the country, pointing to intense efforts by the Pakistani military to hunt down Al Qaeda fugitives in the tribal regions of North and South Waziristan, along the border.

"Even if the tape was dropped here, that doesn't mean that he is here," Sultan said. "Nobody knows where he is, but he cannot be in Pakistan's tribal areas because of the presence of so many troops."

While Pakistan's army has been active in the tribal belt, some have questioned their resolve, noting they allowed an Uzbek terror leader to escape after purportedly surrounding him earlier this year.

Talat Massood, a defense analyst and former Pakistani general, said the terror mastermind was likely in the sprawling port city of Karachi or the rugged tribal belt between Pakistan and Afghanistan.

Wherever he is, Massood said, the emergence of the tape shows bin Laden feels pretty secure. In the video, the Saudi millionaire looks to be in surprisingly good health, considering speculation that he has been holed up in a mountain cave for three years, Massood said.

"The fact that he has the courage to come out shows that he feel protected in his surroundings," Massood said, adding that his hearty appearance "shows that he is probably living in reasonable comfort and he is being taken care of."

The U.S. military in Afghanistan dismissed the new bin Laden tape as "propaganda," and insisted that bin Laden would be caught — but it acknowledged having no fix on the Al Qaeda leader's whereabouts.

"The tape is nothing more than propaganda," U.S. military spokesman Maj. Scott Nelson told reporters. "If you look at Al Qaeda, their organization is being taken down piece by piece.

"Although we don't have a timeframe for when bin Laden will be captured, we have full confidence that he will be."

The image of bin Laden reading a statement was dramatically different from the few other videos of the Al Qaeda leader that have emerged since the Sept. 11 attacks.

In the last videotape, issued Sept. 10, 2003, bin Laden was seen walking through rocky terrain with his top deputy Ayman al-Zawahri, both carrying automatic rifles. In a taped message issued at the same time, bin Laden praised the "great damage to the enemy" on Sept. 11 and mentions five hijackers by name.

In December 2001, the Pentagon released a videotape in which bin Laden was shown at a dinner with associates in Afghanistan on Nov. 9, 2001, saying the destruction of the Sept. 11 attacks exceeded even his "optimistic" calculations.

But in none of his previous messages, audio or video, did bin Laden directly state that he ordered the attacks.

The last audiotape purportedly from bin Laden came in April. The speaker on the tape, which CIA analysts said likely was the Al Qaeda leader, offered a truce to European nations if they pull troops out of Muslim countries. The tape referred to the March 22 assassination by Israel of Hamas founder Sheik Ahmed Yassin.

FOX News' Bret Baier, Ian McCaleb, Anna Persky and The Associated Press contributed to this report.