In the message, posted on a Web site of the Hamas military wing, Cpl. Gilad Shalit said his health is deteriorating and that he needs to go to a hospital. He also said in the brief statement that he is disappointed in the "lack of interest" of the Israeli government in his fate.
The message was released on the anniversary of his June 25, 2006, capture by Hamas-allied militants who tunneled into Israel. Shalit's father and grandfather told Israeli media they believed the voice was Gilad's, although the father expressed doubts to the Ynet news site.
In other developments:
Israeli Prime Minister Ehud Olmert said the tape was "another testimony to the cruelty of Hamas" and that the contents of the tape would be discussed at the summit. However, the prime minister's office said that "there is no change in the government's policy."
"The prime minister has no doubt that the text was dictated to Gilad Shalit by Hamas," a senior official in his office told reporters.
Still, during the summit Monday, Olmert announced, "As a gesture of good will towards the Palestinians, I will bring before the Israeli Cabinet a proposal to free 250 Fatah prisoners who do not have blood on their hands, after they sign a commitment not to return to violence."
It was not believed there was a direct connection between Olmert's announcement and the Shalit tape, only an indirect one.
"The idea is that when Hamas prisoners see the Fatah members getting out, they will pressure Hamas to soften its demands for a prisoner exchange," says Berger. "Also, Israel wants Abbas to get the credit for the release of prisoners and not Hamas."
Olmert also promised to "improve freedom of movement of the Palestinian population in the West Bank substatinally" and reopen trade ties with the territory, saying he wanted to show the Palestinians that "choosing the path of no terror or violence the way of peace and dialogue will bring a better, more comfortable, more peaceful life."
Militants affiliated with the Islamic group Hamas seized Shalit and killed two other soldiers on June 25, 2006, at an army base after tunneling into Israel from the Gaza Strip. Negotiations for his release, mediated by Egypt, have repeatedly broken down and been complicated since Hamas took control of the Gaza Strip two weeks ago.
Shalit, 20, had not been seen or heard from since he was captured.
"I feel really sorry for the way the Israeli government and the Defense ministry carelessly handled my case, the way they turned down the demands submitted to them by al-Qassam brigades," Shalit says on the tape. "It is their duty to respond to such demands in order for me to be set free."
"The same way I have a family; a mother and a father, the thousands of Palestinian prisoners have got mothers and fathers of their own," Shalit said.
"I have spent one year in prison now, and my health condition is deteriorating. I'm in constant need of hospital treatment," he said.
"Shalit is alive and in very good shape," said Abu Mujahid, a spokesman for the Popular Resistance Committees, one of three Hamas-linked groups that captured Shalit, earlier Monday. "His health is good and he's stable. We are treating him according to our religion's instructions on how to deal with war prisoners."
Abu Mujahid said Shalit "doesn't need anything" and is receiving the "best treatment."
Meanwhile, the Israeli human rights group B'Tselem accused the militants holding Shalit of war crimes.
"International humanitarian law absolutely prohibits taking and holding a person by force in order to compel the enemy to meet certain demands, while threatening to harm or kill the person if the demands are not met," the group said. "Furthermore, hostage-taking is considered a war crime."
Hamas is responsible for securing Shalit's release since it effectively controls the security situation in Gaza, B'tselem said. The militants holding the soldier have violated international law further by not allowing Red Cross representatives to visit him, the group said.
Abu Mujahid shrugged off B'tselem's accusations, saying Shalit was captured inside a tank that was used to fight Palestinians.
"Any occupiers on the land are a legitimate target because they are soldiers," Abu Mujahid said. Israel is the one that has committed war crimes by killing Palestinian civilians, he said.
As the summit got under way, Olmert held separate talks with Egyptian President Hosni Mubarak and Abbas. Jordanian King Abdullah II arrived later in Sharm to join them in a four-way meeting later in the evening.
The Arabs and Palestinians are pressing Israel to take immediate advantage of the Hamas militants' expulsion from the coalition government and make quick peace progress despite the Palestinians' split between a Gaza ruled by the Iranian-backed Hamas in Gaza and the West Bank run by Abbas' Western-backed Fatah in the West Bank.
But Israeli Foreign Ministry spokesman Yigal Palmor said major peace negotiations cannot take place until the Palestinians end their divisions. He said Abbas needs to win "the full support of the Palestinians who voted for Hamas."
"Obviously if there's more than one representative of the Palestinians then we cannot negotiate a deal," Palmor said. "So we will need to have and the Palestinians will need to have one sole authorized, recognized interlocutor."
Egyptian President Hosni Mubarak invited Abbas, Olmert and Jordan's King Abdullah II to Sharm el-Sheik in a show of support for the Palestinian president in his struggle with Hamas. The meeting is also meant to show that Abbas of Fatah can move ahead with peacemaking.
Olmert said the gathering would show all sides' "genuine desire to build up a process" of peace-making.
The message supporting Hamas from Ayman al-Zawahri, who is Osama bin Laden's top deputy, marked a major shift by al Qaeda, which in the past criticized Hamas for joining a government with the U.S.-supported Fatah faction.
The audiotape was clearly made after Hamas' takeover of Gaza earlier this month, marking a rapid response from al Qaeda's top leadership to the events. Its authenticity could not be independently confirmed, but it was posted on a Web forum where al-Zawahri has issued messages in the past.
Al-Zawahri urged Hamas to implement Islamic law in Gaza, telling it, "Taking over power is not a goal but a means to implement God's word on earth."
"Unite with mujahedeen (holy warriors) in Palestine ... and with all mujahedeen in the world in the face of the upcoming attack where Egyptians and Saudis are expected to play part of it," he added, suggesting that the two countries intend to attack Hamas to uproot its control of Gaza.
"Provide them (Hamas) with money, do your best to get it there, break the siege imposed on them by crusaders and Arab leader traitors," al-Zawahri, who is Osama bin Laden's top deputy, said, addressing Muslims around the world. "Facilitate weapons smuggling from neighboring countries."
"We can support them by targeting the crusader and Zionist interest wherever we can," al-Zawahri said.