The United States is prepared to offer Israel written security guarantees if it would help to restart stalled Middle East peace talks, the U.S. State Department said on Friday.

"We continue our discussions with the Israelis. If there is a need to put certain understandings in writing, we will be prepared to do that," State Department spokesman P.J. Crowley told a news briefing.

Prime Minister Benjamin Netanyahu has said "intensive" discussions continued to get the necessary "understandings."

"If I receive such a proposal from the American government, I will bring it before the security cabinet and I have no doubt that my colleagues will accept it," he said late Thursday.

Talks between Israeli and U.S. officials aimed at reviving Middle East peace talks have hit snags over the incentives promised by Washington to persuade Israel to resume a freeze of settlement building.

Netanyahu unveiled the U.S. inducements to his cabinet last weekend and appeared hopeful the ministers would back plans for a temporary halt to building in the West Bank to overcome a hurdle to the peace talks.

But an Israeli official said on Friday the United States had not yet provided the guarantees that Israel wanted, with Washington reluctant to commit to paper all the promises Netanyahu says he was offered verbally last week.

The latest snag concerned a pledge that Israel says U.S. Secretary of State Hillary Clinton made to provide the country free of charge 20 F-35 stealth warplanes worth $3 billion.

Politicians said Washington was backtracking and now wanted some sort of payment for the coveted fighter aircraft.

"It looks like the free stealth fighters have slipped," said Benny Begin, a minister from Netanyahu's Likud party who is opposed to the proposed U.S. deal, warning that Washington was setting a trap to extract major concessions later down the line.

"One may wonder if you cannot agree to understandings from one week to the next, what could happen over three months," Begin told the Army Radio on Friday.

Focus on borders

U.S. President Barack Obama invested substantial political capital in persuading the Palestinians to resume direct talks with Israel in early September, after months of mediation.

But, true to their warnings, the Palestinians halted negotiations when Netanyahu refused to extend a 10-month partial settlement moratorium when it expired at the end of September.

Washington hoped its diplomatic and defense enticements would persuade Israel to renew the freeze for 90 days, opening the way for three months of intense negotiations that would focus on the future border of a Palestinian state.

However, Netanyahu's coalition allies demanded a written pledge from the United States to make clear the building freeze did not include occupied land in East Jerusalem and to spell out there would be no U.S. pressure for any subsequent moratoria.

The Palestinians themselves have expressed outrage in private over reports of the U.S. offer, saying it was a bribe to get Israel to fulfill basic international obligations.

The Israeli official said there appeared to be a disconnect between the White House and State Department with Obama unhappy that Clinton had offered so much for such a minimal concession.

However, he added that Netanyahu's office thought a deal could be reached in the coming hours and that the prime minister would get the necessary backing from his cabinet at the weekend.

Political sources say seven ministers are ready to support the plan, while six were firmly opposed, leaving two ministers from the ultra-Orthodox Shas Party holding the balance of power.

Shas is likely to abstain, but they are facing growing pressure from the right to vote against and prevent any halt to settlement building.