US Secretary of State Colin Powell says innocent people are being killed by those providing a haven to people like Osama bin Laden.
He says anyone providing support to organisations such as those headed by bin Laden are attacking civilisation and killing innocent people.
He says his message to the Taliban is the same one he would send to any other regime in any other country.
However Afghanistan's ruling Taliban rulers warned of "revenge" if the United States attacks the hard-line Islamic militia that harbours Osama bin Laden, the main suspect in the terrorist attacks on New York and Washington.
"If a country or group violates our country, we will not forget our revenge," said Taliban spokesman Abdul Hai Muttmain from the militia's headquarters in Kandahar in southern Afghanistan. Muttmain did not elaborate.
Earlier the leader of Afghanistan's Taliban movement defended Osama Bin Laden against accusations he masterminded the terror attacks.
Mullah Mohammad Omar said in a statement released in neighbouring Pakistan that neither Saudi-born Bin Laden nor Afghanistan had the capacity to train the suicide pilots who crashed hijacked aircraft into landmarks in New York and Washington.
Training of pilots is the work of a running government and only such [a] government has the capacity to do so, he said in the statement, read at a news conference by Taliban ambassador to Pakistan Mr Mullah Abdul Salam Zaeef.
"Osama has no pilots and where did he train them? In Afghanistan, there is no such possibility for the training," he said.
The Taliban said it expected to be hit by a huge attack by the United States and vowed that it would take revenge.
"We are ready to pay any price to defend ourselves and to use all means to take our revenge," a spokesman for Mullah Mohammad Omar told AFP.
Afghans have been following the aftermath of Tuesday's attacks in the United States, mostly by listening to foreign radio stations as television is banned. The few international phone lines have been cut for security reasons.
Pakistan said it had not closed its border with Afghanistan, but it was conducting more effective checks on people trying to cross either way.
Pakistan President Gen Pervez Musharraf on Thursday promised full co-operation with the US in helping to track down the terrorists.
AFP &