"We stress the importance of suicide bombings against the enemy, these attacks that have scared Americans and Israelis like never before," he says on the tape, aired Tuesday by the al-Jazeera Arab satellite station.
To buck up the morale of Iraqis facing an onslaught by the world's most powerful military, he tells them not to fear America's laser-guided bombs which failed to kill him when he was trapped in the caves of Tora Bora.
"For more than two hours bombs were dropped on us, about 30 bombs," he says. "But the American forces did not dare storm our stronghold because they were cowards."
U.S. counterterrorism officials in Washington said the audio message was probably a real recording of bin Laden, and that a technical analysis was planned to authenticate it. The officials said it was unclear when the recording was made but said it was probably recent, given all the attention the speaker gave to Iraq.
The White House seized on the tape as evidence that bin Laden and Saddam Hussein are in cahoots.
In an interview with al-Jazeera aired after the tape, U.S. State Department spokesman Richard Boucher said the recording shows that Iraq and al Qaeda "are bound by a common hatred."
"He threatens everybody in the Arab world except Saddam Hussein," Boucher said. "We are saying Iraq is giving a haven to this group."
The speaker on the tape urges Muslims not to cooperate with the United States against Iraq, and criticizes Arab governments who support the U.S. in its efforts to rid Iraq of its alleged weapons of mass destruction.
"Anyone who helps America, from the Iraqi hypocrites (opposition) or Arab rulers ... whoever fights with them or offers them bases or administrative assistance, or any kind of support or help, even if only with words, to kill Muslims in Iraq, should know that he is an apostate."
The speaker also calls on true Muslims to "incite and mobilize the nation ... to break free from the slavery of these regimes who are slaves of America."
He singles out Jordan, Morocco, Nigeria, Pakistan, Saudi Arabia and Yemen.
Before the broadcast, Secretary of State Colin Powell told a Senate panel Tuesday that he had read a transcript of the statement and that it shows why the world needs to be concerned about Iraqi ties to terrorism.
"Once again he speaks to the people of Iraq and talks about their struggle and how he is in partnership with Iraq," Powell said. "This nexus between terrorists and states that are developing weapons of mass destruction can no longer be looked away from and ignored."
Yasser Thabet, a broadcast editor at al-Jazeera, said the tape appears to be authentic because the television station got it through the same means as previous bin Laden statements. He did not elaborate.
"When you listen to the tape, you can tell it's Osama bin Laden's voice," Thabet said.
The last bin Laden tape aired on Nov. 12 on al-Jazeera. Bin Laden, in the statement, promised new terrorist attacks.
As news of the new tape emerged, CIA Director George Tenet and FBI director Robert Mueller were telling the Senate Intelligence Committee that al Qaeda still represented a serious threat to the United States.
With the terrorist threat already rated at its highest level since 9-11, Tenet gave a chilling description of intelligence pointing to a potential attack that could involve a so-called dirty bomb and come as soon as the annual Muslim pilgrimage to Mecca ends this week.
"The information we have points to plots aimed on two fronts: in the United States and on the Arabian Peninsula. It points to plots timed to occur as early as the end of the Hajj, which occurs late this week, and it points to plots that could include the use of a radiological dispersion device as well as poisons and chemicals," Tenet said.
And now the CIA has another piece of intelligence, since in the past the release of bin Laden tapes has been followed in short order by another al Qaeda terrorist attack, reports CBS News National Security Correspondent David Martin.
The U.S. suspects bin Laden of masterminding the 1998 bombings of two U.S. embassies in Africa, the 2000 attack on the destroyer USS Cole, and the Sept. 11, 2001 attacks on the World Trade Center and the Pentagon.
In the wake of those attacks, President Bush vowed to get bin Laden "dead or alive," and launched military strikes on Afghanistan to try to destroy bin Laden and his network. His current whereabouts are unknown, although if he is alive, he is suspected of hiding in the lawless border region between Pakistan and Afghanistan.