Bin Laden's whereabouts are still unknown
Bin Laden's statement came in a new recorded video address, parts of which were broadcast by the Qatar-based satellite television channel al-Jazeera on Saturday. It was not clear when or where it was recorded.
He said the conflict in Afghanistan was "primarily a religious war" between Christianity and Islam.
Condemning US President George Bush's "crusade," he said "it is a certain fact that Bush carried the cross high... Whoever stands behind Bush has committed an act that stands as annulment of their Islam".
Editors at al-Jazeera say the tape was delivered to their offices in the Afghan capital Kabul. It is the fifth statement they have received from Bin Laden's al-Qaeda organisation since the beginning of October - most of them in the form of pre-recorded videotapes - but only the second featuring Bin Laden himself.
The United States says it has evidence that al-Qaeda was responsible for the 11 September attacks in New York and Washington which killed more than 4,000 people.
The White House described Bin Laden's message as "an act of desperation".
In other developments:
UN accused
In his message, Bin Laden castigated the United Nations, saying it had stood by while crimes were committed against Muslims.
"Those who today are referring our tragedies to the United Nations and want to resolve them there are hypocrites, who try to deceive God and His prophet and the believers. Have our tragedies not resulted from the United Nations?"
He said the United Nations had given Arab land "to the Jews" in 1947 - a reference to the UN partition plan for Palestine which resulted in the creation of the state of Israel.
"Those who claim to be leaders of the Arabs and who are still at the United Nations have disavowed what was revealed to Prophet Muhammad," he said.
"Under no circumstances should a Muslim - or any sane person for that matter - resort to the United Nations.
Muslims 'slaughtered'
"The United Nations is only one of the tools of crime. Every day we are being slaughtered and the United Nations does not lift a finger.
"For over 50 years, our brothers in Kashmir have been suffering the worst pain. They have been killed and slaughtered and their honour, blood, and homes are being violated and the United Nations did not lift a finger," he said.
"Today, without any evidence, the United Nations peddles the resolutions that support the unjust and tyrant America against a helpless people who have just come out of a fierce war against the Russian Federation."
He said there was no evidence linking Afghanistan to the 11 September attacks on the United States.
"The entire West, with the exception of a few countries, supports this unfair, barbaric campaign, although there is no evidence of the involvement of the people of Afghanistan in what happened in America.
"The people of Afghanistan had nothing to do with this matter. The campaign, however, continues to unjustly annihilate villagers and civilians: children, women, and innocent people," he said.
US curbs coverage
Al-Jazeera has previously broadcast statements by Bin Laden and a spokesman for his al-Qaeda organisation, Sulaiman Abu Ghaith, which praised the 11 September attacks and warned that more would follow.
Five major US television networks have agreed to limit broadcasts of statements by Bin Laden and his associates.
The White House has said that broadcasts from suspected terrorists could contain anything from incitement to coded messages.
The US has put pressure on Qatar over the television station's coverage.