The Palestinian president, Mahmoud Abbas, warned on Thursday that he would not seek re-election, the latest sign that the Obama administration’s drive to broker a Middle East peace accord, one of President Obama’s key foreign policy goals, has fallen into disarray.

Mr. Abbas, 74, has threatened to step aside before, but coming immediately after Secretary of State Hillary Rodham Clinton’s visit to the region aimed at reviving a peace process between Israel and the Palestinians, his announcement laid bare the deepening tensions over the administration’s failure to extract an Israeli settlement freeze or any concessions from Arab leaders.

Mrs. Clinton’s visit, which she characterized as a success, sowed anger and confusion among Palestinians and other Arabs after she praised as “unprecedented” the offer by the Israeli prime minister, Benjamin Netanyahu, to slow down, but not stop, construction of Jewish settlements in the West Bank.

In a televised speech from his office in Ramallah, Mr. Abbas, who replaced Yasir Arafat five years ago as president of the Palestinian Authority, said, “I have told my brethren in the P.L.O. that I have no desire to run in the forthcoming election,” referring to the Palestine Liberation Organization.

It was not clear whether Mr. Abbas, considered a moderate, pro-Western leader, was determined to quit, although he said his decision was final. He may stay in his post regardless, because it is far from certain that elections he has called for January will be held then and there are few alternatives to him as leader.

What seems clear is that high-level Israeli-Palestinian talks will not resume any time soon, despite Mr. Obama’s pledge in September to redouble American efforts to get the process back on track. A top aide to Mr. Abbas said a large part of his “despondency and frustration” was because of Mr. Obama’s unrealized promises to the region. Without a stop to Jewish settlements, he said, Islamist rivals in Hamas could triumph, and violence could break out.

“There was high expectation when he arrived on the scene,” said the aide, Nabil Shaath, who leads the Fatah party’s foreign affairs department, speaking of Mr. Obama’s pledge to be a peacemaker. “Now there is a total retreat, which has destroyed trust instead of building trust.”

American officials said that they had narrowed gaps since Mr. Obama took office, and insisted that they would continue to push Israel for a freeze to settlement construction. They are also plotting more modest steps, including lower-level contacts between Israelis and Palestinians, which they hope will stabilize the situation while they try to figure out a Plan B.

“We have tremendous respect for President Abbas and the leadership he has offered the Palestinian people for decades,” Mrs. Clinton said Thursday. She said that he talked about his future when they met on Saturday, and that she would continue to work with him, whatever his title.

Mrs. Clinton, administration officials said, tried to dissuade Mr. Abbas from making the announcement. She also urged him to return to the bargaining table with Israel, based on Mr. Netanyahu’s offer to limit settlement construction to 3,000 additional housing units — an offer he rejected.

“This is not to bargain or maneuver,” Mr. Abbas said of his decision not to run. Still, some aides saw it as a gamble to persuade Mr. Obama to announce a full peace plan aimed at ending the Israeli occupation of the West Bank and creating a Palestinian state.

That is unlikely to happen soon, officials said, given the president’s preoccupation with Afghanistan and health care legislation. But the United States is engaged in increasingly urgent diplomacy to bring the two sides together without Mr. Obama’s personal intervention.

On her way home on Wednesday, Mrs. Clinton made an unexpected detour to Cairo to meet with Egypt’s president, Hosni Mubarak, to press him to use his influence with the Palestinians.

There may also be further negotiation between the United States and Israel before a visit by Mr. Netanyahu to Washington next week to address the Jewish Federations of North America. Mr. Obama is also speaking to the group; at the moment, the White House said there were no plans for the two to meet.

Some Middle East analysts said they were puzzled that the administration did not have a backup plan for keeping the process on track in the event that Israel balked at a full freeze.

“Our posture with Israel has weakened, our hope to strengthen the Palestinians has fallen back, and our credibility in the Arab world has been damaged,” said Robert Malley, a peace negotiator during the Clinton administration. “We are victims of events rather than masters of events.”

Among those disruptions is the recent United Nations report criticizing Israel’s actions in Gaza last winter. The United Nations General Assembly voted Thursday to endorse that report, and the administration, backed by a House resolution, does not want it sent to the Security Council.

The report alleges possible war crimes by Israel and Hamas in the fighting, which killed at least 1,200 people, nearly all Palestinian. If the report gets bottled up, said Mr. Shaath, the Abbas aide, “It really is like telling the Palestinians to go back to violence.”

Mr. Abbas called Palestinian elections for January but few people expect them to take place then, if at all, because they require reconciliation between Mr. Abbas’s Fatah and Hamas, which rules in Gaza. Hamas said it would bar voting in Gaza without reconciliation.

The less Mr. Abbas can show that he has gotten from Israel and the United States, the likelier it is that Palestinian voters will turn to Hamas, which calls for the destruction of Israel and enjoys support from Iran.

For all the frustration that the Palestinians and others have over current Israeli policies, Israel faces a deeply divided Palestinian leadership incapable of agreeing to any deal just now.

The Palestinians say they will not start negotiations fresh but want to renew them from where they left off with former Prime Minister Ehud Olmert. He apparently offered more than 90 percent of the West Bank and some form of international or shared rule over Jerusalem.

Mr. Netanyahu has made it clear that Israel wants to retain much more land for security purposes, and that Jerusalem is off the table. Speaking of Mr. Abbas, Qaddoura Fares, another Fatah leader, said on Israel Radio, “I think he’s reached the conclusion that he’s reached a dead end.”

In his speech, Mr. Abbas said, “Peace is more important than any political achievement or any government party or coalition if the results of that government push the region toward disaster or the unknown.” But he added, “We were surprised by the United States’ closing its eyes to the Israeli position.”