Al Qaeda's No. 2 Ayman al-Zawahri denounced last month's Mideast peace conference in the United States as a "betrayal" of Palestinians in a new audiotape posted Friday on an Islamic militant Web site.

The posting was the first reaction by the terror network to the Mideast conference, sponsored by U.S. President George W. Bush and attended by key Arab countries, including Saudi Arabia, Syria and Egypt, as well as Palestinian and Israeli leaders.

The conference relaunched Palestinian-Israeli peace talks after a seven year hiatus — a key breakthrough in the region's core conflict.

"The Annapolis meeting was held to turn Palestine into a Jewish state," the voice, purported to be that of al-Zawahri, said in the 20-minute posting that carried a still photo of the white-turbaned militant against a backdrop photograph from the Maryland conference.

"The czar of Washington invited 16 Arab countries ... to sit in one room, at one table with the Israelis," al-Zawahri said, adding that the conference "witnessed the betrayal deals to sell Palestine."

The authenticity of the Friday's posting could not be independently confirmed, but it appeared on a Web site commonly used by militants.

Al-Zawahri mainly addressed Arabs, urging them to condemn the Annapolis conference and label Mahmoud Abbas as "the traitor," adding that the Palestinian "brother-president sold you out in Annapolis and in its aftermath."

It's time now, he said, for the Muslims to "extent hands to other jihad brothers"— a likely reference to militants beyond the Middle East.

"My brothers in Palestine, we, all Muslims, the Mujahedeen are by your side, in your confrontation with the Zionist enemy," al-Zawahri said. "We will not let you down even if your politicians do."

He also criticizes imprisoned Islamic militants in Egypt, who after years in jail turned away from their militant stance. "Those revisionists are in fact calling for a new American religion that violates God rules," he said.

Al-Zawahri — seen by many some counterterrorism experts to be Al Qaeda's operational chief, rather than bin Laden — is believed to play a large role in directing Al Qaeda's strategy on the ground and issues frequent videos an audiotapes, often laying out the network's doctrinal line.

In most recent postings, al-Zawahri sought to galvanize fighters from North Africa to Afghanistan in a September video. In an audiotape in July, he threatened to retaliate against Britain for having honored novelist Salman Rushdie and railed against Pakistan President Pervez Musharraf.