July 23 (Bloomberg) -- Democratic presidential candidate Barack Obama said he will protect Israel's security and strive to bring about a ``more lasting peace'' in the region as he embarked on the latest stage of his Middle East tour.

``I'm here on this trip to reaffirm the special relationship between Israel and the United States and my abiding commitment to Israel's security,'' Obama told reporters in Jerusalem today after meeting with President Shimon Peres. He said he hoped to ``serve as an effective partner whether as a United States senator or as a president'' in engendering peace.

The Democratic candidate is seeking to burnish his foreign- policy credentials with an eight-day tour of the Middle East and Europe. Polls show foreign policy is his weakness in the presidential campaign against Arizona Senator John McCain, the presumptive Republican nominee.

Obama, 46, arrived in Israel late yesterday after talks with political and military leaders in Afghanistan, Iraq and Jordan. The Illinois senator, on the fifth day of his tour, also met with Israeli Defense Minister Ehud Barak and Benjamin Netanyahu, the leader of the opposition Likud Party, before touring the Yad Vashem holocaust memorial.

``The main focal point of our discussions was the need to stop Iran from developing nuclear weapons,'' Netanyahu told reporters after the talks. ``He said he would never seek in any way to compromise Israel's security and this would be sacrosanct in his approach to political negotiations.''

Direct Diplomacy

Obama has worked to assuage concerns over his support for Israel and his stated willingness to engage in direct diplomacy with leaders such as Iranian President Mahmoud Ahmadinejad. Obama has said the U.S. needs to pursue ``direct and aggressive diplomacy'' with Iran backed by ``tougher'' sanctions.

The U.S. and its European allies accuse Iran of pursuing a nuclear weapons program; Iran insists its activities are peaceful and legal under the nuclear Non-Proliferation Treaty. Ahmadinejad, who has said he wants to see Israel destroyed, said today that Iran will resist pressure from world powers to halt its nuclear program.

``They said Iran has surrendered. They are mistaken,'' the Iranian president said in a speech broadcast live on state television. ``If the great powers think they can sit down and discuss Iran's rights and pressurize Iranians, such a thing won't happen in 100 years.''

Right to Exist

Obama, as well as expressing his commitment to Israel's security, has rejected the Palestinians' demand for the right of those who left Israel to return. He has said the U.S. shouldn't negotiate with Hamas, the Islamic Palestinian group that the U.S. and the European Union consider a terrorist organization, unless it recognizes Israel's right to exist. Obama also backs a plan that has angered Palestinians to move the U.S. Embassy to Jerusalem from Tel Aviv, though he says the matter should be part of negotiations with the Palestinians.

That issue is among the most contentious in Israeli- Palestinian negotiations and may derail President George W. Bush's goal of laying the foundations for a Palestinian state with a peace agreement before he leaves office in January.

``There's a lot of suspicion about Obama in Israel, a feeling he may be more sympathetic to the Palestinians than the current administration,'' said Gadi Wolfsfeld, a political scientist at Hebrew University in Jerusalem. ``They're looking for reassurances that U.S. foreign policy isn't going to change. People in Israel like George W. Bush.''

West Bank

Obama visited Ramallah in the West Bank this afternoon to meet with Palestinian Authority President Mahmoud Abbas and Prime Minister Salam Fayyad. He's then scheduled to travel by helicopter to the southern town of Sderot, which borders the Gaza Strip and was the main target of thousands of Palestinian rockets before Israel and Hamas struck a truce last month. He is to have dinner at Prime Minister Ehud Olmert's official residence in Jerusalem.

Obama will ``experience personally Israel's challenges and its promise in its 60th year,'' Susan Rice, Obama's senior foreign-policy adviser, told reporters in Jerusalem today.

At a joint press briefing with Peres, Obama praised the president's involvement in Israel's 60-year history, describing the country as ``that miracle that has blossomed.''

Peres returned the compliment, saying his greatest wish was for Obama to ``be a great president of the United States.''

Obama's visit to the Middle East coincides with political turmoil in Israel. Olmert faces a widening corruption probe and his political opponents have lashed out after he gave up five Lebanese prisoners to Hezbollah in exchange for the bodies of two Israeli soldiers.

Bulldozer Attack

There was a reminder of the region's wider security challenges yesterday when a Palestinian rammed a bulldozer into a bus and several other vehicles in Jerusalem, injuring 16 people before he was shot and killed by police.

While at Yad Vashem, Obama met and spoke with the Israeli border police officer who shot the Palestinian bulldozer driver, according to Robert Gibbs, Obama's communications director.

Obama is making his fourth stop on a seven-country tour that will take him later this week to Germany, France and Britain. While in Berlin, he is scheduled to give what his campaign aides called a ``substantive speech'' on strengthening the transatlantic relationship.

Earlier today, Obama said the pace of his Middle East tour was beginning to take its toll.

``I could fall asleep standing up,'' he said.

To contact the reporters on this story: Julianna Goldman in Jerusalem at jgoldman6@bloomberg.net; Jonathan Ferziger in Jerusalem at jferziger@bloomberg.net.

Last Updated: July 23, 2008 06:40 EDT