Updated

The United States has formally notified the U.N. Security Council that counterterrorism attacks may be extended beyond Afghanistan.

A legal document sent Sunday to the council reaffirmed the attack on the Taliban was an act of self-defense under the U.N. charter and said the United States reserves the right to strike at terrorist cells beyond the South Asian country, a senior administration official told The Associated Press on Monday.

President Bush made the same point Sunday. It came in his report to the nation that the United States and Britain had unleashed a sustained missile attack on the Taliban, which refused to hand over Usama bin Laden, prime suspect in the Sept. 11 terrorist attacks in New York, Washington and Pennsylvania.

Terrorism is a global phenomenon and the United States sent the document to the United Nations to underscore that force may be used elsewhere, said the administration official, speaking on condition of anonymity.

Bush stopped short of saying he wanted to topple the Taliban regime in Afghanistan, but a top administration official said the president considers that a legitimate goal to ensure that the radical Islamic movement never again harbors terrorists.

The official said Sunday, after Bush ordered airstrikes against targets in Afghanistan, that the action was consistent with Bush's private view that the Taliban must be driven from power.

The ouster of the Taliban would be a major byproduct of the effort to neutralize the Afghan-based bin Laden and his Al Qaeda terrorist organization, said the official.

Bush said in his nationally televised speech Sunday that he gave the Taliban a "series of clear and specific demands" after Sept. 11, including the closure of terrorist training camps and the handing over of Al Qaeda leaders.

"None of these demands were met. And now, the Taliban will pay a price," Bush said.

Secretary of State Colin Powell has become increasingly harsh in his assessment of the implications of the U.S. anti-terror war on the Taliban, as the regime has shown an unwillingness to meet American demands.

On Sept. 25, Powell held out the possibility of U.S. assistance to the Taliban if they were cooperative.

On Oct. 1, his tone was much more stern. He said the Taliban will soon come to the conclusion, if they have not already, that American pursuit of Al Qaeda "might lead to their demise." He added that the first target of U.S. policy is not the Taliban but Al Qaeda.

A senior official said Sunday night that Powell's Oct. 1 comment remains U.S. policy.

Removing an unfriendly regime and replacing it with one that is more congenial can be hazardous.

Afghanistan is known for bitter rivalry among its myriad tribes, and there is no clear notion of what a replacement regime would look like.

Many in Afghanistan believe the country's dethroned king, Mohammad Zahir Shah, 86, is the best hope for reunifying the nation after two decades of bitter conflict. An anti-Taliban rebel group has been active in northern Afghanistan since 1996.

Zahir, based in Rome, has long dreamed of convening a grand national assembly of tribal elders, clerics, intellectuals and land owners to discuss a transition.

The deposed monarch has been receiving increased attention from U.S. officials of late. Last week, he met with the State Department's director of policy planning, Richard Haass. Details were not disclosed.

With the exception of Haiti in 1994, the United States has shied away from explicitly advocating or carrying out the ouster of adversary governments in recent years.

In Haiti, a U.S. invasion force deposed a military regime and reinstated a democratically elected government that had been ousted three years earlier.

In Yugoslavia, the overthrow of President Slobodan Milosevic was never an explicit American goal despite U.S.-led NATO military action against his forces or forces allied with him in 1995 and 1999. Milosevic was deposed by his own people a year ago.

Former President Bush has been widely criticized for not finishing off Iraqi President Saddam Hussein after the United States and other anti-Saddam coalition forces evicted the Iraqi army from Kuwait in 1991.

U.S. officials explained at the time that the U.N. Security Council resolution authorizing the use of force did not call for Saddam's ouster.

In addition, some American troops would have been involved in the occupation of Iraq in the post-Saddam era, which U.S. officials said would have been extremely hazardous.