Turkey's prime minister stormed off the stage during a debate Thursday at the World Economic Forum in Davos, Switzerland, after getting into a shouting match with Israel's president over the fighting in the Gaza Strip.

Turkish President Recep Tayyip Erdogan, left, talks to Israeli President Shimon Peres during a plenary session at the World Economic Forum in Switzerland on Thursday. Erdogan later left the stage after verbally sparring over Gaza with Peres, and being cut off by the moderator. (Alessandro Della Bella/Associated Press)Recep Tayyip Erdogan grew increasingly irritated after appealing for more time from the moderator, Washington Post columnist David Ignatius, to rebut Shimon Peres following the Israeli leader's passionate defence of his country's three-week offensive against Hamas militants.

Ignatius gave Erdogan one extra minute because the session time was ending.

"You kill people," Erdogan told the 85-year-old Israeli head of state. "I remember the children who died on beaches. I remember two former prime ministers who said they felt very happy when they were able to enter Palestine on tanks."

"I find it very sad that people applaud what you said," Erdogan said in Turkish. "You killed people. And I think that it is very wrong."

Ignatius interject, saying the panel couldn't "start the debate again."

"We just don't have time," he said.

"Please let me finish," Erdogan said, to which Ignatius responded: "We really do need to get people to dinner."

The red-faced Turkish leader then said, "Thank you very much. Thank you very much. Thank you very much. I don't think I will come back to Davos after this."

Hamas forced Israel to act: Peres

Peres had told the forum that Hamas forced Israel to act against the thousands of mortars the militant group fired into southern Israel. He also dismissed charges the military operation created a humanitarian crisis in the coastal enclave.

"The tragedy of Gaza is not Israel, it is Hamas," Peres said, in response to Erdogan's comment that the Palestinian territory was an "open-air prison."

"Why did they fire rockets? There was no siege against Gaza. Why did they fight us, what did they want? There was never a day of starvation in Gaza."

With his voice raised and his finger pointed at the Turkish leader, Peres also questioned what Erdogan would do if Istanbul were struck with rockets every night.

In a news conference following the debate, Erdogan said he was upset by the moderation of the debate and Peres's manner toward him.

"I am not just some leader of some group or tribe, so he should have addressed me accordingly," Erdogan said.

Erdogan added he "did not target at all in any way the Israeli people, President Peres or the Jewish people.

"I am a prime minister, a leader who has specifically expressly stated that anti-Semitism is a crime against humanity," he said.

Earlier in the day, Erdogan said U.S. President Barack Obama should help redefine terror and terrorism in the Middle East and use it as the basis for a new U.S. policy there. Erdogan appeared to be referring to the U.S. position toward Hamas and Hezbollah, which the United States considers terrorist organizations.

"I believe that President Obama must redefine terror and terrorist organizations in the Middle East and based on his new definition, a new American policy must be deployed in the Middle East," said Erdogan, whose country has played a key role in trying to mediate among Israel, Syria and the Palestinians.

Gaza aid 'needed urgently': UN's Ban

The heated incident came just hours after the head of the United Nations used the forum to launch an appeal for Gaza aid, as business and economic leaders also discussed a nuclear-armed Iran, the global recession and the new U.S. administration.

UN Secretary General Ban Ki-moon said Gaza needs $613 million US to rebuild following the recent 22-day military campaign between Israel and Hamas.

"Help is indeed needed urgently" to allow UN and other aid groups to "jump into action to help the 1.4 million citizens of the Gaza Strip to recover," he said.

They need food, medicine and shelter, as well as repairs to basic infrastructure such as water and sewers, said Ban, who toured Gaza when both sides declared ceasefires on Jan. 22.

"People have lost their families, they have lost their homes, belongings and livelihoods. Schools, clinics, factories and businesses have been destroyed," he said. Many people are living amid raw sewage, he added.

Israel launched the campaign to end Hamas rocket attacks against the Jewish state on Dec. 27. Roughly 1,300 Palestinians were killed in the conflict, say officials in Gaza, while Israel has reported 13 deaths.

Iran, economy in spotlight

Israeli election frontrunner Benjamin Netanyahu also spoke at the annual gathering of 2,500 business and corporate leaders, saying keeping nuclear weapons out of Iran's hands is more important than the economy.

"What is not reversible is the acquisition of nuclear weapons by a fanatic radical regime.… We have never had, since the dawn of the nuclear age, nuclear weapons in the hands of such a fanatical regime," said the Israeli Likud party leader.

Iran maintains that it is seeking nuclear power for peaceful purposes and not for a weapons program.

The head of OPEC warned the cartel will make production cuts unless demand for oil picks up by the end of the year.

Secretary General Abdalla Salem El-Badri said OPEC members will have reached the group's pledge of a drop of 4.2 million barrels a day by the end of January.

After that, "if we still have some downward problems, then OPEC will not hesitate to take some quantity out of the market," he said.

With files from Associated Press