US President Barack Obama is plunging into the turbulent Middle East on a mission aimed primarily at assuring the United States' top ally in the region that it will not be forsaken amid bitter domestic political squabbles and budget crises in Washington.

Obama arrived in Israel on Wednesday for his first visit as president to the country, saying the US is Israel's "strongest ally and your greatest friend".

Israeli President Shimon Peres welcomed Obama, saying: "A world without US leadership, without her moral voice, would be a darker world. A world without your friendship would invite aggression against Israel".

After the arrival ceremony at the airport, Obama headed to Jerusalem for meetings with Israeli leaders.

Obama faces an Israeli leadership and public anxious to hear the president affirm US commitment to the security of the Jewish state, AP said.

Obama's trip is his second to the Middle East since taking office. He will also be making his first trips as president to the Palestinian Authority and Jordan this week.

He will meet Israeli Prime Minister Benjamin Netanyahu on all three days, hold separate talks in the occupied West Bank with Palestinian President Mahmoud Abbas, and address the Israeli public directly with a speech to students.

US officials say he will try to coax the Palestinians and Israelis back into peace talks. Obama will also seek to reassure Netanyahu that the US is committed to preventing Iran from getting a nuclear bomb, and will discuss ways of containing Syria's conflict.

However, the White House has deliberately minimized hopes of any major breakthroughs, a reversal from Obama's first four years in office, when aides said he would visit the Jewish state only if he had something concrete to accomplish.

"This seems to me to be an ill-scheduled and ill-conceived visit," said Gidi Grinstein, president of the Reut Institute, a think tank in Tel Aviv.

"On the Iranian situation, Israel and the US don't seem to have anything new to say to each other. On Syria, the US doesn't have a clear outlook, and on the Palestinian issue, they are taking a step back and their hands off."

Even though US officials have set expectations low and previewed no significant policy announcements, there is a clear metric to measure the success of Obama's stay in Israel and the West Bank: how much he is able to reverse the perception that his administration is not fully committed to Israel's security.

Qu Xing, president of the China Institute of International Studies, said Obama will give more attention to Israel's security during his second term after facing criticism over his first-term Middle East policies.

Obama came under attack for not having paid enough attention to the Middle East, especially not being committed enough to Israel's security, which resulted in difficulty in resolving Iran's nuclear problem, he said.

Before Obama leaves Ben Gurion Airport for the 45-minute helicopter flight to Jerusalem, he will stop to view an Iron Dome battery, part of the missile defense system that the US has poured hundreds of millions of dollars into developing.

Once in Jerusalem - a potent religious symbol as well as one of the main obstacles to an Israeli-Palestinian peace deal - Obama will make several cultural stops, to see some of the ancient Dead Sea Scrolls and pay tribute to the founder of modern Zionism. The visits intend to show his appreciation for the Jewish people's millennia-old connection to the land that is now Israel as well as the horrors of the Holocaust.

Obama, who has said he is coming to listen, will fly on Thursday by helicopter the short distance between Jerusalem and the West Bank city of Ramallah to meet Abbas.

Direct negotiations between Israel and the Palestinians broke down in 2010 over the issue of Jewish settlements in the West Bank, and Abbas' allies have expressed bitter disappointment over the lack of fresh US moves.

"It's not a positive visit," said Wasel Abu Yousef, a senior official in the Palestine Liberation Organization, led by Abbas.

AP-Reuters-China Daily