By Jeffrey Heller and Matt Spetalnick
WASHINGTON (Reuters) - President Barack Obama takes a break from the Ukraine crisis to hold potentially difficult talks on Monday with Israeli Prime Minister Benjamin Netanyahu on U.S. efforts to keep Middle East peace negotiations alive.
With time running out for a framework Israeli-Palestinian deal to salvage a troubled U.S.-brokered peace process, Obama and Netanyahu sparred in public comments in the run-up to a meeting that will also focus on Iran's nuclear program.
Netanyahu arrived in Washington to a veiled warning from Obama that he would tell the Israeli leader the United States would find it harder to defend Israel against efforts to isolate it internationally if peace efforts failed.
Boarding his flight to the U.S. capital, Netanyahu, who has had a strained relationship with Obama, said that Israel knew how to resist pressure and that he intended to stand firm on what he termed his country's "vital interests."
Secretary of State John Kerry has been trying to persuade Netanyahu and Palestinian President Mahmoud Abbas to agree to a framework deal that would enable troubled land-for-peace negotiations to continue beyond an April target date for a final accord. Abbas is due at the White House on March 17.
"When I have a conversation with Bibi, that's the essence of my conversation: If not now, when? And if not you, Mr. Prime Minister, then who? How does this get resolved?," Obama, using Netanyahu's nickname and borrowing from the Jewish rabbinical sage Hillel, said in an interview with Bloomberg View.
Palestinians seek to establish a state in the occupied West Bank and the Gaza Strip, with East Jerusalem as its capital. Israel captured those areas in the 1967 Middle East war and in 2005 pulled out of the Gaza Strip, now run by Hamas Islamist opposed to Abbas's peace efforts.
Israeli officials say the ball is in Abbas's court, noting his refusal so far to agree to a key Netanyahu demand: Palestinian recognition of Israel as the nation-state of the Jewish people.
Netanyahu is likely to repeat that condition in a policy speech on Tuesday to the pro-Israel lobbying group AIPAC, a traditional podium for some of his most strident speeches.
Palestinians, who point to Israeli settlement-building in occupied territory as an obstacle to peace, say they have already recognized the state of Israel, through official declarations and interim peace deals.
"We are working very close, very intensely with Kerry to try to make this process work," a senior Israeli official said.
The official declined to go into detail about the negotiations, which have been held under a virtual news blackout, but he said Israel was ready to show flexibility, noting that Netanyahu had already described a future Kerry paper as an American document.
That could give Netanyahu - and Abbas - leeway to register reservations that could keep political opponents of a deal at bay.
U.S. officials hope for at least modest progress but do not foresee a breakthrough in the Oval Office meeting, which Netanyahu will follow with talks with Congressional leaders.
"If the president is able to sort of narrow gaps and get closer to where both parties support the ideas and the framework," a senior administration official said, "then that would be great."
But the official added, "It's not like this is going to be another Camp David 2000 ... I wouldn't expect major announcements about the future of the peace negotiations."
While the Palestinian issue and Western powers' nuclear talks with Iran are expected to dominate the Netanyahu-Obama meeting, the Israeli leader's visit is likely to be overshadowed by the crisis in Ukraine.
Obama spent much of the weekend scrambling to ease the situation, including a long phone call with Russian President Vladimir Putin in which the U.S. president warned of economic and political isolation if Moscow did not withdraw its troops from Ukraine's Crimea region.
On the Iranian issue, there is little expectation on either side that the leaders will be able to bridge their fundamental differences.
Netanyahu, whose country is widely believed to be the Middle East's only nuclear-armed nation, denounced as a "historic mistake" an interim deal that world powers reached with Iran in November under which it agreed to curb sensitive nuclear activities in return for limited sanctions relief.
He has demanded that any final deal completely dismantle Tehran's uranium enrichment centrifuges, a position at odds with Obama's suggestion that Iran, which says its nuclear program is peaceful, could be allowed to enrich on a limited basis for civilian purposes.
"They're not going to have a meeting of the minds on this," said Daniel Kurtzer, a former U.S. ambassador to Israel.
(Editing by Eric Walsh)