After a frustrating week of shuttle diplomacy here in which the Obama administration failed to persuade Israelis and Palestinians to renew peace talks, leaders of the two sides are heading to the United States to make their cases again that the administration should push the other harder.

President Obama will meet in New York on Tuesday with Benjamin Netanyahu, the prime minister of Israel, and Mahmoud Abbas, the Palestinian president. The Palestinian prime minister, Salam Fayyad, will also be in New York. On Monday, Israel’s defense minister, Ehud Barak, will meet in Washington with Defense Secretary Robert M. Gates and other officials.

The White House said it did not expect to achieve any breakthroughs, but senior administration officials said Mr. Obama decided to go ahead with a meeting on the sidelines of the United Nations General Assembly to show his determination to get the process moving again.

“This is the next step in a determined diplomatic process that started on Day 1 of this administration,” said Tommy Vietor, a White House spokesman.

Palestinian leaders say the sources of the frustration could not be clearer: Israel’s refusal to freeze settlement building in the West Bank and East Jerusalem in keeping with earlier commitments, and its insistence on holding peace talks without agreeing to deal with the key issues of Jerusalem and Palestinian refugees.

“Without a settlement freeze or an agreement to talk about the core issues, there is no point in starting the negotiations,” Saeb Erekat, the top Palestinian negotiator, who is also going to New York, said by telephone. “Ask Mr. Netanyahu if he is willing to negotiate on Jerusalem and on refugees. He refuses. And we all know that if he ever accepted, he would lose his governing coalition.”

Mr. Netanyahu’s coalition is largely right wing and pro-settlement.

Israeli officials say they will seek to focus American attention away from settlements and on what they consider the real issues: Iran’s nuclear ambition and Palestinian intransigence.

“I fear the Palestinians are going to miss a huge opportunity,” Mr. Barak said by telephone. “There is a president who says determinedly, ‘I am going to put my political capital into making sure there is an independent Palestinian state and solve all the core issues in two years.’ If we bear in mind Israel’s security needs and the demand that a final agreement means an end to the conflict, this is an opportunity that must not be missed.”

Israeli officials acknowledge their unwillingness to stop all Israeli building in the West Bank, but said this was because the lives of Israeli settlers must go on until a deal is reached.

“I am not willing to dry out, to turn my back on a quarter of a million Israeli citizens,” Mr. Netanyahu said in an interview with Israel’s Channel 10 on Thursday. “It is clear that the fate of the settlements and of the borders will have to be decided. But they can’t be decided until the talks start.”

When asked if he would be willing to remove settlements as part of the solution, Mr. Netanyahu said that he saw no reason to volunteer concessions before the talks.

Another top Israeli official said that the Palestinians should not object to the construction of kindergartens or other new public buildings inside existing settlements because if those settlements are ultimately transferred to the Palestinians, those buildings would go to them.

“We are not going to destroy any infrastructure when there is a deal,” the official said, speaking on the condition of anonymity because he was discussing a subject under negotiation. He added that Israel had taken a number of steps in the West Bank to help the Palestinians — removing roadblocks, encouraging the economy, helping the recent Fatah congress take place — but that the Palestinians were stuck on a “no-brick policy” regarding settlements, meaning no construction at all.

Mr. Erekat said that the Palestinians did not want Israeli kindergartens, they wanted their land.

On Tuesday, Mr. Obama plans to meet with each side separately before seeing them together.

While administration officials acknowledge that the president’s special envoy, George J. Mitchell, has not been able to close the gaps between the two sides, they point out that Israel voted in a new government soon after Mr. Obama took office, and that tensions in the region were still high from the war in Gaza. Given where it started, these officials insist, the situation has improved.

For his part, Mr. Barak said he would focus in Washington on maintaining Israel’s qualitative military edge, on Iran and on the Palestinians.

Israel is in the process of developing a three-tiered missile defense system aimed at stopping short-, medium- and long-range missiles, some of it with American help. The system will require a couple more years, according to most estimates.

Mr. Barak said that concern about Iran remains a top priority and that Israel wants the diplomatic efforts being pursued by the Americans to be limited, well defined and followed by tough sanctions. He reiterated that he removes no option from the table, a reference to the possibility of a military assault on Iranian nuclear facilities.

In an interview last week with the Israeli newspaper Yediot Aharonot, Mr. Barak said that Iran did not pose an existential threat to Israel, because it did not yet have a nuclear weapon and because even if it developed one, Israel could protect itself.

The statement raised eyebrows in the United States because it seemed to suggest that Israel might be growing less concerned about Iranian nuclear weapons. But in his telephone interview, Mr. Barak said this was not the case. He simply wanted to urge his fellow citizens to refrain from panic over the Iranian program. Some Israeli leaders have compared the Iranian threat to that of the Nazis in the 1930s.

“I don’t buy the relevance of comparing the situation with that of Europe in 1938,” Mr. Barak said. “Then, the hope for a normal Jew looking into the future was to flee. We are not in such a situation. We can defend ourselves against any kind of threat.”

Mr. Barak said a central challenge for the United States now was how to handle the nuclear weapons of North Korea, because that would greatly influence Iran.

“North Korea is developing long-range missiles in the backyard of China and Russia and nothing happens to them,” he said. “When the Iranian leadership asks themselves, ‘Should we be worried or just go through the ritual of defying and cheating?’ the answer depends on what happens to North Korea. A coherent move toward blocking nuclear proliferation should start with North Korea. It would have very positive ramifications for blocking Iran.”