In the brief excerpt aired on al-Jazeera television, al-Zawahri's wording seemed to indicate he recorded the tape before the Nov. 2 elections, when President Bush won re-election over Democrat John Kerry.
"The results of the elections do not matter for us," al-Zawahri said in the excerpt, which lasted about three minutes. "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."
It was unclear if al-Jazeera planned to show more of the tape later.
Al-Zawahri also said the United States is trying to coerce the Muslim world through force, to satisfy Israel and to achieve the U.S.'s own interests.
And he said the fall of Baghdad was only a prelude to what the whole Muslim world might be subjected to by the United States.
He also addressed the American people, urging them to deal with Muslims "with respect and exchange and based on an exchange of mutual interests."
He advised the Americans to choose between one of two things: "Either you choose to treat us with respect and based on an exchange of interests ... or we will continue to fight you until you change your policies."
The bearded and bespectacled Zawahari sat before a white background, half-covered with a blanket. His voice sounded calm and steady, as in previous tapes.
Days before the U.S. election, bin Laden said in video footage that the United States must stop threatening the security of Muslims if it wants to avoid "another Manhattan." While bin Laden did not directly warn of new attacks, the al Qaeda leader and Sept. 11 mastermind warned, "There are still reasons to repeat what happened."
In an audio tape purportedly released by Osama bin Laden's deputy last month, Zawahri called for attacks on U.S. and British interests everywhere, according to a broadcast Friday by Al-Jazeera television.
Al-Zawahri is an Egyptian-born surgeon and the closest aide to the al Qaeda terrorist group leader.
Before that, the previous message purportedly from al-Zawahri surfaced in September just before the third anniversary of the Sept. 11 attacks in the United States. In that videotape, a bearded al-Zawahri proclaimed the United States will be defeated in Iraq and Afghanistan.