Dealing a blow to the Obama administration’s efforts to restart Middle East peace talks, Secretary of State Hillary Rodham Clinton failed Saturday to persuade the Palestinian leader to accept an Israeli proposal that would slow but not stop the construction of Jewish settlements in the West Bank and East Jerusalem.

The Palestinian leader, Mahmoud Abbas, insisted that Israel must halt all construction of housing units before broader negotiations could begin. He rebuffed an Israeli proposal — developed by Prime Minister Benjamin Netanyahu and relayed by Mrs. Clinton — to complete about 3,000 units and temporarily freeze other construction, the chief Palestinian negotiator, Saeb Erekat, said after the meeting.

“This is a nonstarter,” Mr. Erekat said. “Mr. Netanyahu has a choice, settlements or peace, and he has chosen settlements.”

Mrs. Clinton’s meetings, which came after a three-day trip to Pakistan, followed on President Obama’s pledge last month to redouble American efforts to revive the peace process. But on a marathon day of diplomacy that took her from the Persian Gulf emirate of Abu Dhabi to Israel and then on to Morocco, she discovered that if anything, the hurdles to a peace negotiation have grown larger.

American officials insist Mrs. Clinton did not push Mr. Abbas to accept the Israeli proposal in her two-hour meeting with him, which was hastily arranged and took place in Abu Dhabi,. But she made clear later she was eager to narrow the gap between the two sides.

“We know that negotiations often take positions that then have to be worked through, once the actual process starts,” she said at a news conference in Jerusalem, where she met with Mr. Netanyahu.

She also markedly softened her tone on whether Israel should cease all settlement construction, something she and Mr. Obama have demanded since early in the administration. While Mrs. Clinton said the administration’s desire to see a complete freeze had not changed, she characterized Mr. Netanyahu’s offer of “restraint” on settlements as “unprecedented.”

And she conspicuously avoided criticizing the demolition of Palestinians’ houses in East Jerusalem, though she said her opposition to it had not changed. In March, on her first visit to the Middle East as secretary of state, Mrs. Clinton strongly condemned the demolitions, which Palestinians say are aimed at squeezing them out and would hamper the creation of a Palestinian state.

In recent days, the municipal authorities in Jerusalem have ordered the demolition of more houses.

For his part, Mr. Netanyahu accused the Palestinians of using settlements as a pretext to avoid negotiations.

“We think we should sit around that negotiating table right away,” he said. “I think what we should do on the path to peace is to simply is get on it, and get with it.”

The administration’s efforts to revive peace negotiations have been unsuccessful, largely for reasons having to do both with its own ambitious goals and with unfavorable regional politics.

In addition to the settlement freeze, Mr. Obama has tried to extract a series of reciprocal confidence-building gestures from Israel’s Arab neighbors — for example, opening Israeli trade offices in those countries, or allowing Israeli passenger planes to fly over Arab territory.

Saudi Arabia rebuffed these requests, which made it less likely that other Arab countries would follow with such gestures. In Israel, the election of a right-wing government under Mr. Netanyahu dimmed the prospects for a settlement freeze, given the pressures from his coalition.

Mr. Netanyahu has offered a moratorium on the construction of new settlements in the West Bank, but not in East Jerusalem. He would also allow additional construction in the West Bank to support the growing families of settlers — a provision known as “natural growth.”

The publication of a United Nations report alleging war crimes in Gaza last winter greatly complicated the calculus. Mr. Netanyahu said that if the report, which accuses both sides of war crimes, were advanced in the United Nations, it would kill off talks before they started.

The United States pressed the Palestinian Authority to bottle up the report in the United Nations Human Rights Council, which it agreed to do. But that set off a political conflagration at home, and Mr. Abbas reversed himself, voting to forward the report to the Security Council.

With his credibility damaged and with elections looming in January, Mr. Abbas has been reluctant to enter talks. And he is citing Mr. Obama’s tough line on settlements as a reason to hold out.

“Secretary Clinton told us,” Mr. Erekat, the chief Palestinian negotiator, said, “that the United States considers settlements to be illegitimate and does not accept the annexation of East Jerusalem.”