CAIRO, Egypt — Al-Qaida's deputy leader denounced last month's Mideast peace conference in Annapolis, Md., as a "betrayal" of Palestinians in a new audio message posted Friday on an Islamic militant Web site.

It was the first reaction by the terrorist network to the Mideast conference, sponsored by President 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 Ayman al-Zawahri, said the 20-minute posting that carried a still photo of the white-turbaned militant against a backdrop of a photograph from the 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 criticized 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's rules," he said.

Al-Zawahri — seen by many some counterterrorism experts to be al-Qaida's operational chief, rather than Osama bin Laden — is believed to play a large role in directing al-Qaida's strategy on the ground and issues frequent video and audio messages, 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 July message, he threatened to retaliate against Britain for having honored writer Salman Rushdie and railed against Pakistan President Pervez Musharraf.