The U.S. ambassador to Afghanistan, Zalmay Khalilzad, says he believes that country's presidential election will go forward as planned next month, though he expects stepped-up attacks by Taleban remnants and other opponents of the U.S.-backed government in Kabul.

Mr. Khalilzad exudes optimism about the election process and the long-term prospects for democracy in Afghanistan. But he is not minimizing the threat to the planned October 9 voting posed by the Afghan government's hard-line opponents, including Taleban remnants, al-Qaida, and followers of warlord Gulbuddin Hekmatyar.

In a talk with State Department reporters, Mr. Khalilzad called the presidential election a "defining event" that will determine the country's direction for at least the next five years.

He said those who oppose democracy also realize this and will try to disrupt the election, perhaps with a ferocity akin to the 1968 "Tet Offensive" by communist forces against the then-government of South Vietnam.

"They want to disrupt it, undermine it," the ambassador said. "I expect that as we go toward elections, and on election day, they'll try to disrupt, in particular, the area where they're going to be mostly active is along the border with Pakistan to the south and east. They may also try some spectacular attacks a la perhaps a Tet offensive kind of thing, to go after and do some things in some of the towns, including Kabul."

Mr. Khalilzad said Afghan government troops and police, U.S.-led coalition forces, and the NATO-led International Security Assistance Force, ISAF, are ready for such an eventuality.

He said attacks aimed at the election process thus far, including the killing of some people merely for carrying voter registration cards, have only strengthened the resolve of Afghans, more than 10 million of whom he said have registered to cast votes.

Under questioning, the U.S. envoy rejected the notion the United States might look for an exit from Afghanistan after the election. He said American interests suffered greatly when the United States walked away from Afghanistan with the end of Soviet occupation in 1989, and he said that history will not be repeated.

"The Afghans fear abandonment, I have to tell you that. That's their big fear, abandonment. But my instructions are that no, we have learned from our mistakes," he said. "We will not do that again. Afganistan's success is our success, and Afghanistan's failure, God forbid, will be our failure. The United States will be there for as long as it takes."

Mr. Khalilzad is in the United States to join Secretary of State Colin Powell for talks with Afghan President Hamid Karzai and other related meetings next week on the sidelines of the U.N. General Assembly in New York.

The U.S. envoy said he hopes Mr. Karzai will be able to have more talks there with Pakistani President Pervez Musharraf to follow up a meeting last month in Islamabad in which they reaffirmed a common commitment to fight terrorism.

Mr. Khalilzad said Pakistan has been doing a "very good" job uprooting al-Qaida elements from the border region with Afghanistan. However, he said the United States would like to see more Pakistani effort with regard to the Taleban, which he lumped with al-Qaida as a terrorist group, though a regional one.