WASHINGTON — Upbeat claims from President Trump over an imminent peace deal to end the war with Iran were met with deep skepticism Friday across the Middle East, where Iranian and Israeli officials questioned the prospects for a lasting agreement that would satisfy all parties.

The outlines of an agreement began to emerge that would provide Iran with a major strategic victory — and a potential financial windfall — allowing the Islamic Republic to leverage its control over the Strait of Hormuz to exact significant concessions from the United States and its ally Israel as Trump presses for a swift end to the conflict.

In a series of social media posts and interviews with reporters, Trump announced that the strait was “fully open,” vowing Tehran would never again attempt to control it. But Iranian officials and state media said that conditions remained on passage through the waterway, including the imposition of tolls and coordination with the Islamic Revolutionary Guard Corps.

Iranian diplomats posted threats that its closure could resume at any time of their choosing, and warned that restrictions would return unless the United States agreed to lift a blockade of its ports. Trump had said Friday that the blockade would remain in place.

“The conditional and limited reopening of a portion of the Strait of Hormuz is solely an Iranian initiative, one that creates responsibility and serves to test the firm commitments of the opposing side,” said a top aide to Iran’s president, dismissing Trump’s statements on the contours of a deal as “baseless.”

“If they renege on their promises,” he added, “they will face dire consequences.”

In an overture to Iran, Trump said Israel would be “prohibited” from conducting additional military strikes in Lebanon, where the Israeli government of Prime Minister Benjamin Netanyahu seeks to prevent Hezbollah, an Iranian proxy militia, from rearming, a potential threat to communities in the Israeli north.

But in a speech delivered in Hebrew, Netanyahu would say only that Israel had agreed to a temporary ceasefire, while members of his Cabinet warned that Israel Defense Forces operations in southern Lebanon were not yet finished. A top ally of the prime minister at a right-wing Israeli news outlet warned that Trump was “surrendering” to Iran in the talks.

It was a day of public messaging from a president eager to end a war that has proved historically unpopular with the American public, and has driven a rise in gas prices that could weigh on his party entering this year’s midterm elections.

Yet, Republican allies of the president have begun warning him that an agreement skewed heavily in Tehran’s favor could carry political costs of its own.

Trump was forced to deny an Axios report Friday that his negotiating team had offered to release $20 billion in frozen Iranian assets in exchange for Tehran agreeing to hand over its fissile material, buried under rubble from a U.S. bombing raid last year.

That sum would amount to more than 10 times what President Obama released to Iran under a 2015 nuclear deal, called the Joint Comprehensive Plan of Action, that was the subject of fierce Republican criticism in the decade since.

“I have every confidence that President Trump will not allow Iran to be enriched by tens of billions of dollars for holding the world hostage and creating mayhem in the region,” said Sen. Lindsey Graham (R-S.C.), a strong supporter of the war. “No JCPOAs on President Trump’s watch.”

Still, Trump said in a round of interviews that a deal could be reached in a matter of days, ending less than two weeks of negotiations.

He claimed that Tehran had agreed to permanently end its enrichment of uranium — a development that, if true, would mark a dramatic reversal for the Islamic Republic from decades developing its nuclear program, and from just 10 days ago, when Iranian diplomats rejected a U.S. proposal of a 20-year pause on domestic enrichment in favor of a five-year moratorium.

He said Iran had agreed never to build nuclear weapons — a pledge Tehran has made repeatedly, including under the Nuclear Nonproliferation Treaty, in a religious decree from then-Supreme Leader Ayatollah Ali Khamenei, and in the 2015 agreement — while continuing nuclear activities viewed by the international community as exceeding civilian needs.

And he repeatedly stated that Iran had agreed to the removal of its enriched uranium from the country, either to the United States or to a third party. Iranian state media stated Friday afternoon that a proposal to remove the country’s highly enriched uranium had been “rejected.”

Iran’s agreement to allow safe passage for commercial vessels through the Strait of Hormuz is linked to a ceasefire in Lebanon that the Israeli Cabinet approved for only a 10-day period. Regardless of whether it holds or is extended, Israeli officials said their military would not retreat from its current positions in southern Lebanon — opening up Israeli forces to potential attack by Hezbollah militants unbound by a truce brokered by the Lebanese government.

The Lebanese people, Hezbollah officials said, have “the right to resist” Israeli occupation of their land. Whether the fighting resumes, the group added, “will be determined based on how developments unfold.”

An Iranian official threw cold water on the prospects of reaching a comprehensive peace deal in the coming days, telling Reuters that a temporary extension of the current ceasefire, set to expire Tuesday, would “create space for more talks on lifting sanctions on Iran and securing compensation for war damages.”

“In exchange, Iran will provide assurances to the international community about the peaceful nature of its nuclear program,” the official said, adding that “any other narrative about the ongoing talks is a misrepresentation of the situation.”

Trump told reporters Friday that the talks will continue through the weekend.

While Trump claimed there aren’t “too many significant differences” remaining, he said the United States would continue the blockade until negotiations are finalized and formalized.

“When the agreement is signed, the blockade ends,” the president told reporters in Phoenix.

Times staff writer Ana Ceballos contributed to this report.