By ARON HELLER, Associated Press Writer

Tuesday, March 9, 2010 at 3:02 a.m.

JERUSALEM — The U.S. will back those willing to "take risks for peace," U.S. Vice President Joe Biden said Tuesday during the highest-level visit to Israel by an Obama administration official.

Biden said he was pleased that Israelis and Palestinians had agreed this week to resume indirect peace negotiations with U.S. mediation. His two-day visit to Israel seemed clearly aimed at assuaging Israeli concerns that President Obama has been less friendly to Israel than his predecessors, saying the relationship has always been a "centerpiece of American policy" and offering effusive praise.

"Progress occurs in the Middle East when everyone knows there is simply no space between the United States and Israel," he said, a day after the U.S. announced Israelis and Palestinians had agreed to begin indirect peace talks, breaking a 14-month deadlock.

The announcement of indirect talks, which will be held through a U.S. mediator, marked President Barack Obama's first diplomatic breakthrough in the Israeli-Palestinian conflict. But the new peace push is sure to face enormous challenges, including sharp divisions among the Palestinians and a hardline Israeli government seen as unlikely to make wide-ranging concessions.

Biden said he hoped the beginning of indirect talks would be "a vehicle by which we can begin to allay that layer of mistrust that has built up in the last several years."

"The United States will always stand with those who take risks for peace," Biden said standing beside Israeli Prime Minister Benjamin Netanyahu. He told the Israeli leader, "you're prepared to do that." The appearance, which included warm banter between the two men, ended with Netanyahu telling Biden that trees had been planted outside Jerusalem in honor of the vice president's late mother. "My love for your country was watered by that Irish lady," Biden responded.

Polls show that Israelis have come to see Obama as less sympathetic to Israel than previous presidents. Biden's comments appeared aimed at softening the administration's image both among Israelis and their American supporters, whose backing is seen as crucial ahead of November's congressional elections.

The vice president also offered assurances that the U.S. remained committed to Israel's well-being, speaking of the administration's "total, unvarnished commitment to Israel's security."

Iran appeared to loom large in Biden's discussions with Netanyahu, and in the joint appearance with the Israeli leader Biden said: "We are determined to prevent Iran from acquiring nuclear weapons."

Israel has been pushing for stricter international sanctions targeting Iran's nuclear program, and has refused to rule out a military strike if sanctions fail.

Obama began his term with a push for Mideast peace, prodding Israel to freeze its construction of West Bank settlements that swallow up land the Palestinians want for a future state. But that call came just as Netanyahu took over in Israel, and though the Israeli leader scaled back settlement construction, he would not accept a full freeze. Obama's insistence on a total settlement freeze is seen by many in the region to have backfired by encouraging Palestinians to stake out a position that was politically untenable for Israel's hawkish government.

Biden called Netanyahu's partial freeze "significant," but the Palestinians are still saying they will not talk directly to Israel unless it freezes settlement building completely.

But hours after Biden's arrival Monday, the U.S. announced the sides would begin indirect peace negotiations. The fact that the discussions will be held through a U.S. mediator attests to the estrangement between the Israelis and Palestinians, who have been speaking to each other directly, on and off, since the early 1990s. The agreement to restart talks was marred the same day by an Israeli announcement of approval for 112 new housing units in a West Bank settlement, drawing Palestinian condemnation.

To reach a peace agreement, the sides will have to agree on the border between them, including a division of Jerusalem. They will also have to work out a compromise on the fate of Palestinians who lost their homes when Israel was founded in 1948 and agree on how to guarantee Israel's security after it leaves the high ground and strategic depth of the West Bank.

Despite numerous rounds of peace talks over nearly 20 years and heavy U.S. involvement, the sides have been unable to bridge the gaps on those tough issues.

With the Islamic militant Hamas openly committed to Israel's destruction and now in charge of the Gaza Strip, and with Israel governed by a coalition suspicious of concessions to the Palestinians, there are reasons to doubt whether an agreement will be possible this time.

On the other hand, the fact that some Israeli hard-liners, like Netanyahu himself, have come to accept the idea of Palestinian independence, and that the Palestinians in the West Bank are now ruled by moderates, might offer some hope.