But the immediate danger for the Taleban was the artillery and rocket fire raining on the north as the resurgent Northern Alliance captured Kari and marched on the strategic city of Mazar-i-Sharif.
Russian President Vladimir Putin promised to funnel arms to the rebels, while neighbouring Kazakhstan offered the US use of airports and military bases. American attack helicopters are already reported to be standing by in Uzbekistan.
Tribes in west and central Afghanistan are also fighting the Taleban and there are growing signs the regime could splinter.
But bin Laden and the Taleban were unmoved by the pressure.
In a statement released to an Arab television channel, bin Laden said his al Qaeda forces remained "steadfast on the path of jihad [holy war]".
He called on Muslims in Pakistan to do all they could to stop US troops invading from there, and promised to support the children of three people who died in anti-US demonstrations in Pakistan.
"We hope that they are the first martyrs in Islam's battle in this era against the new crusade and Jewish campaign led by the big crusader Bush under the flag of the cross."
Taleban leader Mullah Mohammed Omar repeated his claim that the US goal was "to eliminate Islam", and the Taleban claimed they were mobilising 300,000 more fighters to defend their borders against invasion.
US Secretary of State Colin Powell said the Afghan resistance could help the US achieve its objectives - to capture bin Laden and neutralise al Qaeda. Northern Alliance delegates are taking part in talks in Rome with former King Zahir Shah to ease the way for a post-Taleban government. Officials from the UN, US and European Union are involved.
Another potential leader in a new government, Abdul Haq, left Rome for Pakistan to coordinate opposition assaults. The famed guerrilla commander, who helped drive the Soviets out, said Afghan fighters stood a better chance of ousting the Taleban than foreigners unfamiliar with the brutal terrain.
The approach of winter in Afghanistan's mountainous north-east is another factor worrying military analysts and UN relief workers.
Much of the border area is expected to be deep in snow within a month, turning any sustained military campaign into a logistical nightmare.
In other developments:
* The US backtracked on Powell's promise to release evidence linking bin Laden to the attacks, saying most of the information was secret.
* Saudi Arabia joined the United Arab Emirates in severing ties with the Taleban.
* Border patrols intercepted a rocket launcher and other heavy weapons being smuggled from Afghanistan to Taleban supporters in Pakistan.
* The number arrested or detained by US authorities investigating the suicide strikes passed 350 and Attorney-General John Ashcroft said nearly 400 more remained at large.
Map: Opposing forces in the war against terror
Afghanistan facts and links
Full coverage: Terror in America
