The White House has said the statement by Osama bin Laden broadcast by Al-Jazeera television on Saturday demonstrated "how isolated he is from the rest of the world".
"This is just more propaganda," said White House spokeswoman Anne Womack. "That shows how isolated he is from the rest of the world."
Bin Laden, who is accused of masterminding the September 11th terrorist attacks on New York and Washington, launched a fierce diatribe against the United Nations, blaming it for the Muslims' suffering.
In a videotape broadcast earlier Saturday by Al-Jazeera, the Saudi-born Afghan-based militant also said the United States had no proof to justify its strikes on Afghanistan, which began nearly four weeks ago after the ruling Taliban militia refused to hand him over to Washington.
In the statement bin Laden launched his strongest appeal to fellow Muslims to join his holy war against the West since the US strikes on Afghanistan, denouncing those who support Washington as traitors to Islam.
"Rise in support of your religion. Islam is calling you," said bin Laden, the US's prime suspect for the hijack attacks.
Appearing in a new videotaped statement, the Saudi-born militant sought to convince Muslims that it was their duty to side with him against what he called a Christian "crusade" led by President Bush against Islam.
"This war is primarily a religious war," he said.
He appeared in footage broadcast by the Arabic satellite channel al-Jazeera and appeared pale and became emotional near the end of his statement. It was not clear when it was recorded. His comments were laced with Koranic verses and the sayings of Mohammed, his clearest effort since the attacks to define the Afghanistan conflict in religious terms.