Washington (CNN) The United States is beginning to prep allies for a spring rollout of its plan for Middle East peace, with President Donald Trump's senior adviser and son-in-law, Jared Kushner, outlining the timing and methodology of the plan at the Middle East security conference in Warsaw, Poland.

During a presentation Thursday, Kushner confirmed that the Trump administration will not release its peace plan prior to Israel's elections in April, according to a senior administration official present in the room.

After a series of meetings at the Munich Security Conference this weekend, Kushner will spend the end of the month, alongside Jason Greenblatt, Trump's former personal lawyer who is now an adviser on Israel, on a trip to present economic elements of the plan to wealthy Arab allies.

Kushner's presentation was the first chance international diplomats had to hear about the Trump administration's efforts to resolve the decades-long conflict. The President's son-in-law and his team have kept a tight wrap on the substance of his plan, refusing to share details with traditional US partners on Mideast peace efforts, including allies in the region and in Europe.

The silence surrounding the plan has become a source of frustration and uncertainty that some diplomats worry could eventually scuttle the proposal's chances.

Fears about the plan

Kushner has rebuffed major US allies' requests to circulate the plan, one diplomat said, as he and his team are reportedly fearful that its contents would leak out and the proposal would be scuttled before they have a chance to roll it out.

But the diplomat told CNN that the silence and secrecy could contribute to the plan's failure. This diplomat said major US allies hope to see the proposal early so they can identify snags or build support, but they have been met with silence, which has left them frustrated.

"We're not being told anything," a second diplomat said. These allies very much want to help out in the process if they can, but they feel left out and many have voiced frustration.

One concern the allies have is they will learn about the substance of the plan so late in the game that it's impossible to weigh in with changes -- and that it could be something they can't support.

One source familiar with discussions between countries said this is particularly a concern in Arab countries that will get briefed on the economic portion of the proposal -- which they will be asked to fund.

A new style

"This is not likely to go well -- the economic piece is seen in the region as shorthand for trying to buy the Palestinians off," the source said. "It's important to get Arab buy-in. You need the main Arab players to urge the Palestinians not to say no. ... You want them to go to (Palestinian Authority President) Abu Mazen (Mahmoud Abbas) and say, 'Don't dismiss it. Give it a thought. Let's see what elements you can live with.' For that to happen," the source said, Arab countries "have to feel that they are co-owners of this thing. They have to be privy" to the substance of the plan.

That source cautioned that while almost nothing is known about the proposal, it is expected to skew heavily in favor of Israel and is expected to use nonlegal language, not the internationally established and accepted jargon associated with past peace proposals.

The style and choice of the language, the source said, is an attempt to speak directly to Palestinians in the hope that they can be used to pressure Abbas to accept the plan. It is not expected to mention a two-state solution, the source said, but explains how Palestinian self-determination will manifest itself.

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In Poland on Thursday, Israeli Prime Minister Netanyahu told those gathered at Kushner's briefing that he will not prejudge the plan before it is put out and he hopes that Palestinians, who refused to attend the meeting, will do so as well, according to the senior administration official in the room.

Talks between the US and Palestinians broke down after Trump's December 2017 decision to recognize Jerusalem as the capital of Israel, a rejection of international consensus that the issue should be resolved toward the end of peace negotiations.

The US has also closed the Palestinian diplomatic presence in Washington and cut aid to Palestinian refugees, deepening the chill between the two sides, leading Palestinians to declare that the US had forfeited its position as a neutral arbiter in the conflict.

A diplomat familiar with the peace plan discussions said the US had asked Saudi Arabia's ambassador to the US, Prince Khalid bin Salman, to try to get Palestinian leadership to attend the summit. He was unsuccessful.

No reason to attend

An Arab diplomat said the United Arab Emirates had also asked the Palestinians to come to Warsaw -- but they said no. Their reasoning, the diplomat said, is that the US has not done anything in their favor, giving them little reason to attend the conference.

"We can try to talk and give some advice, but can't force them to do anything," a Saudi diplomat told CNN. "We do not have the power to tell people not to go or to go. But we always try to bridge opinions when we can."

Jonathan Schanzer, a Middle East scholar and senior vice president at the Foundation for Defense of Democracies, noted that the killing of Washington Post journalist Jamal Khashoggi has reduced Saudi political capital and made them more risk-averse, "but may see other Arab states assume more of a public role. But the Saudis will keep doing it if the US asks."

The senior administration official said rollout of the peace plan has been delayed by a number of external factors. Kushner and his team were supposed to visit the countries that are to be involved with the economic portion of the proposal in October, but that got pushed back after Khashoggi's murder.

US elections in November created another roadblock, along with the partial government shutdown in January. But some analysts said the delay until after April's elections may be about helping Netanyahu, an old family friend of Kushner's who is facing corruption allegations and political headwinds.

April elections

Even if the Israeli leader wins the elections in April, the political baggage he carries -- including the possibility he may get indicted on corruption charges -- may make it hard for him to assemble a coalition. But if the administration puts forward a peace plan after the election, various Israeli political parties might want to join the coalition to be part of that process.

"Netanyahu might be keen on having the plan coming out after the election and before coalition formation, so it could be a pivot point to broaden his coalition," said David Makovsky, of the Washington Institute of Near East Policy.

Schanzer said the proposal's rollout could just as easily sink the prime minister, who has drawn some red lines about what he will and will not accept.

Netanyahu's conditions include an Israeli security presence along the Jordan River -- the western edge of any future Palestinian state -- for decades. And he has said in the past that he will not divide Jerusalem, even as Palestinians say they want to establish their capital there as well.

"I think it could be a bomb they are going to drop on the Israeli political system. ... No matter when this thing is rolled out, there is a possibility that this plan blows up Netanyahu's chance at being prime minister even if he wins the election," Schanzer said. "This could disrupt his ability to hold together a coalition because of what he would be asked to give up."