Looking for an elusive path back to negotiations, U.S. officials said the Obama administration is exploring security guarantees for the Jordan Valley, a section of the West Bank that stretches along the border with Jordan.
Israel has long demanded the guarantees as part of any treaty establishing an independent Palestine, though the issue has been overshadowed by more sensitive matters.
Although Palestinians have a measure of self-rule in other areas, the Jordan Valley is part of the 60 percent of the West Bank still under full Israeli control nearly two decades after interim peace accords granted the Palestinians autonomy elsewhere.
Netanyahu has said he wants Israel to maintain some sort of security presence in the valley as part of any agreement. Israel fears an independent Palestine without a sufficient international or Israeli presence could lead to a buildup of military equipment and extremists along whatever becomes the final boundary — and lead to more conflict.
One idea floated in the past included joint Israeli-Palestinian patrols of the mostly desert area home to some 60,000 Palestinians.
The strategy during Kerry's visit, according to U.S. officials, is to leverage movement by Abbas on security guarantees into possible concessions from Netanyahu on Jewish settlement construction in the West Bank and east Jerusalem — lands Israel captured in the 1967 Mideast War and which the Palestinians hope to include in their future state. More than 500,000 Israelis now live in the territories.
The officials spoke on condition of anonymity because they weren't authorized to speak publicly about internal deliberations. It's unclear what kind of reception such a proposal would get from the Palestinians, who've insisted on a complete freeze in Israeli settlements for negotiations to begin anew.
"We are still at the 'let's see what's possible' stage," Nuland told reporters. "The secretary is committed to using his strong relationships with both leaders to encourage them to be open, to be creative, to be prepared for compromises and to work hard to build trust between them, to increase confidence and to create that environment where we're able to help them."
She added, in not especially optimistic terms: "We'll see what is possible, but it's really too early to know."
The Palestinians have big expectations for Kerry's diplomacy, which is likely to persist in an intensive manner over the next several weeks.
The big goals center on seeing settlement construction halted and Israel's 1967 boundaries agreed to as the baseline for a Palestinian state. Netanyahu has never outlined his vision for how Israel and Palestine should be separated, but he rejects a return to the 1967 lines and says talks should resume without preconditions.
Smaller confidence-building measures may be possible at this stage. The Palestinians also are looking for Israel to free some 120 prisoners held since before the interim peace accords were signed in 1993. And Abbas has said he'd meet Netanyahu if there is a prisoner release, although not for formal negotiations.
"The key to success for the efforts to re-launch the peace process is Israel's implementation of its commitments, especially stopping settlement activities, releasing prisoners and accepting the two-state solution based on the 1967 borders," said Saeb Erekat, the chief Palestinian negotiator.
Kerry may have an easier time cementing the diplomatic progress Obama brokered between Turkey and Israel during the president's trip to the region two weeks ago.
The two countries were once strong allies, but their relations spiraled downward after Israel's 2010 raid on a Turkish flotilla bound for Gaza. Eight Turks and one Turkish-American died.
Turkey had demanded an apology as a condition for restoring ties. Netanyahu refused until Obama arranged a telephone call between the Israeli leader and Turkey's Prime Minister Recep Tayyip Erdogan. Erdogan, however, is still holding up full normalization of relations until a compensation agreement is worked out Israel significantly loosens its Gaza blockade.