Bin Laden does not speak in the video
The Arab TV station al-Jazeera has broadcast a videotape which it says shows Osama Bin Laden and his top aide Ayman al- Zawahri.
The Qatar-based channel said the recording had probably been made in April or early May in an "undetermined mountain area".
The video footage does not show the men speaking, but al-Jazeera has also aired two audio recordings which it attributes to the al-Qaeda leader and his deputy.
The videotape was aired on the eve of the second anniversary of the 11 September attacks on New York and Washington, which have been blamed on Bin Laden's al-Qaeda network.
On one of the audiotapes, a man purported to be Bin Laden praises the 11 September attackers. In the other a voice said to be that of Mr Zawahri calls for Iraqi guerrillas to '"bury" US troops.
The BBC's security correspondent Frank Gardner says the latest video is important because it is the first new footage of Bin Laden seen in more than a year, even though there is no independent confirmation that it was actually filmed this year.
Bin Laden was shown in mountainous terrain
It was almost certainly shot in Afghanistan or Pakistan, he says.
The voice said to be Bin Laden's called for emulation of the hijackers who crashed airliners into the World Trade Center and Pentagon on 11 September, 2001.
"Whoever wants to learn loyalty and courage in support of religion should learn from [Said] al-Ghamdi, Mohammed Atta, Khaled al-Mihdhar, Ziad Jarrah, Marwan al-Shehhi and the others", the speaker said.
The other speaker, said to be Mr Zawahri, urged Iraqis to "rely on God and devour the Americans, like lions devour their prey - bury them in the Iraqi graveyard".
The speaker also called on Palestinians to resist Israel.
"We call on them to stand fast on the path of jihad [holy war] and not to be deceived by the tricks of America and its agents who bless the roadmap to hell. Palestine will only be liberated with jihad."
Referring to the 11 September attacks and the US campaigns in Afghanistan and Iraq, he warned that "what you have seen so far is only the first skirmishes and the beginning of the clash".
"The real battle, however, has not started yet. So prepare yourselves to be punished for your crimes."
Soon after the videotape was broadcast, US President George W Bush delivered a speech in Virginia warning that al-Qaeda "still plots against our people".
He did not refer to the videotape in his message, marking the 11 September anniversary.
"The forces of global terror cannot be appeased, and they
can't be ignored. They must be hunted, they must be found and
they will be defeated," he said.
"We will keep them on the run... Al-Qaeda has lost nearly two-thirds of its known leaders, either captured or killed. The terrorists have lost access to some $200m."
He said that in Iraq "a collection of killers is desperately trying to shake the will of the civilised world," but "America will not be intimidated".