Washington's special Mideast envoy launched a last-ditch push Tuesday to wring an Israeli promise to curtail settlement construction and persuade the Palestinians to attend a high-profile U.S. meeting meant as a prelude to peacemaking.

George Mitchell's meeting with Israeli Prime Minister Benjamin Netanyahu will be crucial to U.S. President Barack Obama's credibility in the Arab world and as a Mideast peace broker. If Mitchell fails to wrest significant concessions from Netanyahu, the Arab world is likely to become skeptical of Obama and the unprecedented pressure he has put on Israel to halt settlement expansion.

Palestinian President Mahmoud Abbas has repeatedly said he would not resume official talks with Israel unless settlement construction comes to a total halt. Aides have said, however, that he might agree to an informal sitdown with Netanyahu next week on the sidelines of a U.N. meeting in New York.

Mitchell met first with Netanyahu on Tuesday, a day after the Israeli leader rejected U.S. calls for a settlement freeze. He said plans to build nearly 3,000 new apartments in the West Bank will remain on course and there will be no restrictions on expanding Jewish neighborhoods in east Jerusalem, Netanyahu said.

Palestinians claim both areas for a future state that would also include the Hamas-run Gaza Strip.

Netanyahu reiterated his willingness to suspend for a limited time any other new construction in the West Bank, hoping that will be enough of an overture for the Americans and the Palestinians. But that tradeoff hasn't elicited much enthusiasm in either quarter.

As they entered their meeting, Mitchell expressed hope of bringing "this phase of our discussions to early conclusion" and to "move forward in our common search for comprehensive peace in the region."

After the meeting, which lasted more than two hours, Netanyahu's office put out a pager statement saying the talks were "good" and that the two men would hold an unscheduled second session on Wednesday morning.

Mitchell hopes in his meetings with Netanyahu, and later Tuesday with Abbas, to bridge the differences and set the stage for the first encounter between the Palestinian and Israeli leaders since Netanyahu took office in March. Both will be in New York next week for the opening of the U.S. General Assembly, and there has been speculation that Obama would join an Abbas-Netanyahu meeting.

Israeli officials said Tuesday that President Shimon Peres met clandestinely with chief Palestinian negotiator Saeb Erekat in Jerusalem last week to try to pressure the Palestinians to meet with Netanyahu. The Israeli presidency is a ceremonial position, but Peres carries cachet in the international community for advancing the landmark 1993 accord between Israel and the Palestinians, which won him a Nobel Peace Prize.

The officials spoke on condition of anonymity because the visit had been secret.

An Abbas-Netanyahu meeting would not necessarily signal a watershed. Israel and the Palestinians have held multiple rounds of talks without producing an accord ending decades of conflict.

And this time things could be even tougher.

Netanyahu grudgingly has accepted the concept of Palestinian statehood — but only under intense heavy U.S. pressure and with conditions the Palestinians reject. He is ideologically committed to Israel's settlement enterprise and reluctant to make the territorial concessions necessary to strike a deal, arguing they would compromise Israel's security.

Palestinian militants' takeover of the Gaza Strip after Israel's evacuation of the territory in 2005 has made these fears more tangible.

Abbas, for his part, would be skewered at home for agreeing to launch negotiations without first assuring a complete settlement freeze.

For more than a year, he held talks with Netanyahu's dovish predecessor, Ehud Olmert, that ultimately went nowhere. That has cost Abbas credibility among his own constituency, which has narrowed considerably since Islamic Hamas militants overran Gaza in 2007, leaving him controlling only the West Bank.