Whilst researching, I cam across UN Security Council Resolution 1267 on Afghanistan - Taliban Sanctions, adopted October 15, 1999, which includes the following:

Strongly condemning the continuing use of Afghan territory, especially areas controlled by the Taliban, for the sheltering and training of terrorists and planning of terrorist acts, and reaffirming its conviction that the suppression of international terrorism is essential for the maintenance of international peace and security,

Deploring the fact that the Taliban continues to provide safe haven to Usama bin Laden and to allow him and others associated with him to operate a network of terrorist training camps from Taliban-controlled territory and to use Afghanistan as a base from which to sponsor international terrorist operations,

Noting the indictment of Usama bin Laden and his associates by the United States of America for, inter alia, the 7 August 1998 bombings of the United States embassies in Nairobi, Kenya, and Dar es Salaam, Tanzania and for conspiring to kill American nationals outside the United States, and noting also the request of the United States of America to the Taliban to surrender them for trial (S/1999/1021),

[…]

2. Demands that the Taliban turn over Usama bin Laden without further delay to appropriate authorities in a country where he has been indicted, or to appropriate authorities in a country where he will be returned to such a country, or to appropriate authorities in a country where he will be arrested and effectively brought to justice;

It sure helped that the Security Council did all that “condeming”, “deploring” and “demanding”, now didn’t it?