''I wish to assure President Bush and the U.S. government of our unstinted cooperation in the fight against terrorism,'' President Gen. Pervez Musharraf said in a statement after a late-night meeting Wednesday with his military. ''The world must unite to fight terrorism.''

The United States urged Pakistan Thursday to close its border with Afghanistan and to cut off funding for terrorist groups, a senior Bush administration official said in Washington.

The U.S. government also asked Pakistan for permission to fly over its territory in the event of military action, the official said on condition of anonymity.

The U.S. request came after Secretary of State Colin Powell had focused on Afghanistan and Pakistan during an appeal for support from world leaders - Afghanistan for harboring bin Laden and Pakistan for its proximity the Saudi exile's operations and its own record of support for Afghanistan's ruling Taliban.

''As we gather information and as we look at possible sources of the attack, it would be useful to point out to the Pakistani leadership at every level that we are looking for and expecting their fullest cooperation and their help and support,'' Powell said Wednesday.

On Thursday, Powell identified bin Laden as a prime suspect in the attacks and said he was telephoning Musharraf to seek ''a specific list of things that we think would be useful for them to work on with us.''

After they talked for nearly 10 minutes, State Department spokesman Richard Boucher said they had a positive conversation and Powell received a commitment of cooperation.

In his statement, Musharraf did not specify what type of cooperation Pakistan was offering. He met Thursday with new U.S. ambassador Wendy Chamberlin. Afterward, she said there had been a ''meeting of minds'' and that Musharraf had pledged ''full support.'' The envoy did not elaborate.

Deputy Secretary of State Richard Armitage met with Maleecha Lodhi, the Pakistani ambassador to Washington, on Wednesday.

''The United States officially called for full support and cooperation on Wednesday, and asked what Pakistan could do to help,'' said a senior Pakistani Foreign Ministry official who spoke on condition of anonymity.

The request conveyed by the State Department was seen by the Foreign Ministry as an indication of possible U.S. military action against Afghanistan, the official told The Associated Press. However, he said the specifics of Pakistan's potential assistance were not discussed.

Since Tuesday's attacks, there has been speculation about a retaliatory strike against Afghanistan. The United Nations and many international aid organizations have withdrawn their foreign workers, fearing an attack.

Asked at a news conference Thursday whether Pakistan would cooperate with the United States in a possible military strike against the Taliban, presidential spokesman Maj. Gen. Rashid Qureshi said it would be premature to speculate.

If the United States pushes Pakistan for cooperation in a concrete action against the Taliban, Musharraf will face a stark choice.

Cooperating with the United States in an attack on Afghanistan could cause a backlash from militant Muslim groups in Pakistan, one of three countries that recognizes the Taliban government. The others are Saudi Arabia and the United Arab Emirates.

The Taliban are supported by militant Islamic groups in Pakistan. Followers of the Pakistani groups are well-armed and strongly anti-American.

''If the government allows Pakistan to be used for attacks on Afghanistan it would be a great a treachery,'' said Maulana Samiul Haq, the leader of the Afghan Defense Council, an umbrella group of Pakistan's religious political parties and Islamic militant groups. He said the group would urge street protests.

However, Pakistan could benefit from helping Washington. It suffers economic sanctions imposed by the United States and much of the Western world because of its 1998 nuclear tests.

Pakistan's Inter-Services Intelligence agency has been involved in Afghanistan since the 1970s, and is believed to have been the force behind the Taliban, which took control of most of Afghanistan in 1996. It is believed to have better intelligence information about Afghanistan and the Taliban than any other country.

The Taliban have refused to hand over bin Laden, who is wanted by Washington in the deadly bombings of two U.S. embassies in East Africa in 1998. Washington fired cruise missiles at eastern Afghanistan following those bombings.