According to Palestinian, Arab and European officials who have heard Mr. Abbas’s version of the conversation, Crown Prince Mohammed bin Salman presented a plan that would be more tilted toward the Israelis than any ever embraced by the American government, one that presumably no Palestinian leader could ever accept.
The Palestinians would get a state of their own but only noncontiguous parts of the West Bank and only limited sovereignty over their own territory. The vast majority of Israeli settlements in the West Bank, which most of the world considers illegal, would remain. The Palestinians would not be given East Jerusalem as their capital and there would be no right of return for Palestinian refugees and their descendants.
The White House on Sunday denied that was its plan, saying it was still months away from finalizing a blueprint for peace, and the Saudi government denied that it supports those positions.
That left many in Washington and the Middle East wondering whether the Saudi crown prince was quietly doing the bidding of Mr. Trump, trying to curry favor with the Americans, or freelancing in order to put pressure on the Palestinians or to make any eventual offer sound generous by comparison. Or perhaps Mr. Abbas, weakened politically at home, was sending out signals for his own purposes that he was under pressure from Riyadh.
Even if the account proves incomplete, it has gained currency with enough players in the Middle East to deeply alarm Palestinians and raise suspicions about Mr. Trump’s efforts. On top of that, advisers have said the president plans to give a speech on Wednesday in which he would recognize Jerusalem as the capital of Israel, even though both sides claim it, a declaration that analysts and regional officials say could undermine America’s role as a theoretically neutral broker.
“There is constant speculation and guessing about what we are working on, and this report is more of the same,” said Joshua Raffel, a White House spokesman. “It is not reflective of the current state of the plan we are working on or the conversations we have had with regional players.”
The Saudi ambassador to the United States, Prince Khalid bin Salman, said in an email that “the Kingdom remains committed to a settlement based on the Arab peace initiative of 2002, including East Jerusalem as the capital of a Palestinian state based on the 1967 borders. To suggest otherwise is false.”
Mr. Trump assigned the effort to reach what he calls the “ultimate deal” to his son-in-law, Jared Kushner, aided by Jason Greenblatt, his top negotiator, and other aides. After nearly a year of listening tours to the region, they are developing a comprehensive plan but have kept details under wraps.
“We know what’s in the plan,” Mr. Kushner said in a rare public appearance on Sunday at the Saban Forum, a Middle East conference in Washington hosted by the Brookings Institution. “The Palestinians know what discussions we’ve had with them. The Israelis know what discussions we’ve had with them.”
Prince Mohammed’s meeting with Mr. Abbas happened less than two weeks after Mr. Kushner had visited the prince in Riyadh to discuss the peace plan.
Word of the proposal has shaken up a region already wrestling with multiple conflicts, astonishing Arab officials and Western observers alike. Palestinian officials from both Mr. Abbas’s Fatah party and its rival, Hamas, said they had found the plan insulting and unacceptable.
“If the Palestinian leadership were to accept any of the above, the Palestinian people would not let them remain,” said Hassan Yousef, a senior Hamas leader in the West Bank who is also a member of the Palestinian legislature.
Adding to the shock for Palestinians, according to Palestinian officials from Fatah and Hamas, as well as a senior Lebanese official and several other people briefed on the matter, was the claim that Prince Mohammed had told Mr. Abbas that if he would not accept the terms, he would be pressed to resign to make way for a replacement who would.
Several of the officials said the prince had offered to sweeten the agreement with vastly increased financial support to the Palestinians, and even dangled the possibility of a direct payment to Mr. Abbas, which they said he had refused.
Prince Khalid, the Saudi ambassador, said Saudi Arabia fully supported “the Palestinian leadership under President Abbas” and “has not and will not interfere in the internal affairs of the Palestinians.”
Mr. Abbas’s spokesman, Nabil Abu Rudeineh, dismissed the accounts of the Riyadh meeting and the Saudi proposals as “fake news” that “does not exist,” and said the Palestinians were still awaiting a formal proposal from the United States.
But the main points of the Saudi proposal as told to Mr. Abbas were confirmed by many people briefed on the discussions between Mr. Abbas and Prince Mohammed, including Mr. Yousef, the senior Hamas leader; several Western officials; a senior Fatah official; a Palestinian official in Lebanon; a senior Lebanese official; and a Lebanese politician, among others.
Ahmad Tibi, a Palestinian member of the Israeli Parliament, described a similar set of ideas that he said the Palestinians had received from the Americans and Israelis: a Palestinian state with only “moral sovereignty” and noncontiguous territory and without East Jerusalem as the capital; no Israeli settlement evacuation; and no right of return for Palestinian refugees.
And word of the plan has worried even some of the United States’ closest allies, who are eager for clarification from the White House.
An adviser to President Emmanuel Macron of France, speaking on condition of anonymity, said French officials had heard a version of some of the Saudi proposals, which sounded very similar to Israel’s opening bid and not acceptable to Palestinians.
He said that France had told the Americans that if they wanted to start discussions, they should proceed, but should remember that France and many other countries also have interests and concerns in the region.
Mr. Abbas was alarmed and visibly upset by the proposal, the Fatah official said.
Mr. Yousef, of Hamas, said in an interview that there was consternation that Mr. Abbas and his aides had not revealed and denounced the suggestions publicly.
“As long as they remain quiet about this, we do have fear of something like this happening,” Mr. Yousef said, adding that if Mr. Abbas received any offer, it is “very important” that he “tells the Palestinian people that ‘we were offered 1,2,3,4 and that we refused this offer.’”
While the proposals may sound far-fetched on their face, they have deeply alarmed Palestinian and Arab officials because they come in a context of fast-moving new dynamics in the region.
Prince Mohammed, 32, is very close to Mr. Kushner, 36, both young men without much foreign policy experience who see themselves as creative reformers able to break with the ossified thinking of the past.
And the Saudi prince has made clear that his top priority in the region is not the Palestinian-Israeli issue, the fulcrum of Arab politics for generations, but confronting Iran.
Regional officials and analysts say they believe he might be willing to try to force a settlement on Palestinians in order to cement Israeli cooperation against Iran.
Western and regional officials said Saudi Arabia’s main goal seems to be normalization of relations with Israel, which would be difficult if the Palestinian struggle remains a regional cause. Saudi Arabia currently has no official relations with Israel but they have been widely reported to have secretly cooperated for years on security issues.
But several of Prince Mohammed’s foreign policy efforts so far have sputtered, reflecting what many officials and diplomats in the region say is a lack of understanding of basic regional dynamics, or a willingness to ignore them.
His move to isolate Qatar, in part for being too close to Iran, has if anything forced it to become closer to Iran. Last month, his gambit to pressure the Lebanese prime minister, Saad Hariri, to resign — to isolate Iran’s Lebanese ally, Hezbollah — backfired, leaving Mr. Hariri still in place and arguably stronger than before.
Alarms began to go off across the region last month, when Mr. Abbas started making phone calls to political leaders in the region after he had left Riyadh.
One Lebanese government official who received a call was most surprised by what he said was a Saudi suggestion that the Palestinians could have Abu Dis, a suburb of East Jerusalem, as their capital.
Abu Dis is separated from the city by a wall built as part of Israel’s separation barrier.
The Lebanese official said no Arab could accept that kind of gamesmanship, adding that no one could propose that to a Palestinian unless a person lacking experience was trying to flatter the family of the American president.
A senior Lebanese official and a Lebanese politician, both briefed on the discussions, said Mr. Abbas had been told he had two months to accept the deal or he would be pressured to resign.
A Palestinian official in Lebanon said one idea floated by the Saudis was to compensate the Palestinians for the loss of West Bank territory by adding territory to the Gaza Strip from Egypt’s Sinai Peninsula, a rocky desert plagued lately by jihadist attacks. A Western official said Egypt already had rejected that idea.
But the news on Friday that Mr. Trump would recognize Jerusalem as the Israeli capital suggested that ideas once considered beyond the pale are now seriously being considered.
Recognizing an Israeli capital there, even without explicitly denying the Palestinians one, would overturn decades of consensus among international peacemakers that any change in Jerusalem’s status must come as part of a negotiated deal.
Palestinian officials already have said that move would threaten any chance of a two-state solution and could even provoke a new Palestinian uprising.
On Sunday, Saeb Erekat, the Palestinian negotiator, said in a statement that the move would create “international anarchy and disrespect for global institutions and law.”
He said the United States would be destabilizing the region, discouraging supporters of a peaceful solution and “disqualifying itself to play any role in any initiative towards achieving a just and lasting peace.”