ISLAMABAD - Secretary of Defense Donald Rumsfeld has made a surprise visit to Afghanistan. He met with the Afghan president, who called for stronger military ties with the United States.

Afghanistan's president, Hamid Karzai, is seeking an expanded role for the U.S. military in his country and used Mr. Rumsfeld's surprise visit to press his case.

Mr. Karzai still faces significant challenges from Taleban and al-Qaida linked militants in many parts of the country.

During a joint news conference, Mr. Karzai called for a longer-term relationship with the United States.

"A strategic security relationship that would enable Afghanistan to defend itself," said Hamid Karzai.

Mr. Rumsfeld reiterated Washington's commitment to Afghanistan, but did not discuss specific arrangements.

Mr. Rumsfeld is now in Pakistan, where he is expected to meet with President Pervez Musharraf, a key U.S. ally in the war on terror.