Israeli and Palestinian negotiators meet this week to work toward the long-shot U.S. goal of achieving a comprehensive peace deal this year that even Israeli Prime Minister Ehud Olmert says is out of reach.

U.S. Secretary of State Condoleezza Rice plans to meet separately, and then together, in Washington on Wednesday with Israeli Foreign Minister Tzipi Livni and former Palestinian Prime Minster Ahmed Qurei, the two sides' lead negotiators.

The three-way talks will be the latest in a series Rice has convened this year but, like the Israeli-Palestinian bilateral negotiations, have yet to produce tangible progress toward ending the six-decade conflict.

Beyond the intrinsic difficulty of resolving such controversial issues as the delineation of borders, the fate of Palestinian refugees and the status of Jerusalem, the effort is further hindered by the political divisions on both sides.

Olmert is under a cloud because of a corruption investigation, while the Palestinians are split between the Hamas-ruled Gaza Strip and the West Bank, where Palestinian President Mahmoud Abbas' Fatah movement holds sway.

As a result, there is deep skepticism among Israelis, Palestinians and independent analysts that there is any chance of achieving U.S. President George W. Bush's goal of "resolving all outstanding issues" before he steps down in January.

At a peace conference he held in November at Annapolis, Maryland, Bush also said the two sides had agreed to "make every effort to conclude an agreement before the end of 2008."

Olmert said on Monday there could be agreement on borders and the Palestinian refugees this year but that a full deal resolving claims to Jerusalem was not a "viable possibility."

Israel, in a claim not recognized internationally, regards all of Jerusalem as its capital. The Palestinians want Arab East Jerusalem as the capital of a future Palestinian state.

Even U.S. officials have begun to say privately they are thinking about how best to nurture the peace process so as to hand it over to their successors.

Asked if they were mounting a final push to get the talks moving, one U.S. official said, "It's fairer to say that we are keen to build the sort of traction needed for things to move in the right direction, so that the next administration gets a situation that's as manageable and productive as possible."

Bruce Riedel, a former National Security Council official who worked on the Middle East during the Clinton administration, said there was still hope in the Bush administration for a partial deal, for example on borders excluding Jerusalem.

SHOWING TOUGHNESS VERSUS TAKING RISKS

The obstacles to a comprehensive agreement are legion and start with the divisions within the Israeli political class and among the Palestinians.

Olmert is grappling with an investigation into allegations he accepted envelopes stuffed with cash from a U.S. fundraiser and double-billed for travel expenses. Olmert denies wrongdoing but says he will step down if indicted.

According to opinion polls, Livni is the favorite to follow Olmert as head of the Kadima party. She could face a challenge from Transport Minister Shaul Mofaz, a former defense chief known for his tough tactics in crushing the Palestinian uprising that began after the last peace talks failed in 2000.

Another potential successor, should new Israeli elections be held, is Defense Minister Ehud Barak, who tried and failed to strike a peace deal when he was prime minister in 2000.

Barak and Mofaz are also visiting Washington this week.

Jon Alterman, director of the Middle East program at the Center for Strategic and International Studies think tank in Washington, said the Israeli political jockeying diminished the chances of an agreement.

"It makes it extraordinarily hard because they can't lead, they can only compete for leadership, and competing for leadership means showing toughness rather than taking risks," he said.

'TOO LITTLE WATER, AND TOO LATE'

Israeli officials described Livni as wary of releasing an interim document setting out Israeli territorial concessions to the Palestinians because it could be used against her in any Kadima primaries. They said any Israeli compromise on borders without a Palestinian compromise on refugees could backfire.

Barak's talks on Tuesday are expected to touch on Iran, which Israel views as an "existential" threat because of its suspected pursuit of nuclear weapons.

A U.S. official said Washington's focus would be on Israeli commitments under the 2003 U.S.-backed "road map" peace plan to halt settlement activity and to ease the lot of Palestinians on the West Bank by removing checkpoints and other barriers.

Retired U.S. Gen. James Jones has conducted a confidential assessment of how Israel and the Palestinians are meeting their commitments, which include Palestinian efforts to curb violence against Israelis.

The U.S. official said the Jones report was critical of Israel but did not provide details. Analysts, however, said Israel had done too little on the West Bank.

"Compared to the lofty rhetoric of Annapolis and to the strategy of making the Fatah-ruled West Bank a garden that would be in contrast to the desert of a Hamas-ruled Gaza, I think what we have seen is too little water, and too late," said Riedel.