CAIRO, Egypt – Osama bin Laden’s top deputy vowed in a videotape aired yesterday to keep fighting America until Washington changed its policies.

In a brief excerpt broadcast on Al Jazeera TV, Ayman al-Zawahiri offered Americans “one last advice” for dealing with Muslims, adding, “I am sure that they will not heed it.”

“You have to choose between one of two methods to deal with Muslims: either on mutual respect and exchange of interests, or to deal with them as if they are spoils of war,” Mr. al-Zawahiri said. “This is your problem and you have to choose yourself. You have to realize that we are a nation of patience and endurance. We will stand firm to fight you with God’s help until doomsday.”

The bearded and bespectacled Mr. al-Zawahiri sat before a brown background with a gun leaning against the wall. One shoulder was covered by a brown blanket. His voice sounded calm and steady, as in previous tapes.

An American intelligence official, speaking on the condition of anonymity, said authorities have “a high degree of confidence” that the message was from Mr. al-Zawahiri.

The intelligence official noted that this video resembles one made in September featuring a similar brown fabric background and weapon. But, the official added, that does not mean it was made at the same time or actually is the same video.

In a reference apparently showing that the latest tape was made before the November 2 presidential election in America, Mr. al-Zawahiri said there was no difference between President Bush and Democratic nominee Senator Kerry of Massachusetts.

“As for elections in America, the two candidates are competing to win the satisfaction of Israel,” Mr. al-Zawahiri said. That fact proved “there will be no solution with America without forcing it to surrender to justice,” he said.

He added: “The results of the elections do not matter for us. Vote whoever you want, Bush, Kerry, or the devil himself. This does not concern us. What concerns us is to purge our land from the aggressors.”

Days before the election, Mr. bin Laden said in similar video footage that America must stop threatening the security of Muslims if it wanted to avoid “another Manhattan” – referring to the September 11 attacks. Addressing the American people, Mr. bin Laden also said, “Your security is not in the hands of Kerry, Bush, or Al Qaeda. Your security is in your own hands….Any state that does not mess with our security has naturally guaranteed its own security.”

It was unclear if Al Jazeera planned to show more of the latest Mr. al-Zawahiri tape.

America has offered a $25 million reward for the capture of Mr. bin Laden and Mr. al-Zawahiri, who are believed to be hiding in the border area of Afghanistan and Pakistan.

Two of Mr. al-Zawahiri’s messages were aired in September and October: an audiotape on October 1 that called on young Muslims to attack America, and a videotape broadcast on Al Jazeera on September 9 in which he predicted that America would ultimately be defeated in Iraq and Afghanistan.