US officials say a deal has been agreed in principle with Iran to reopen the Strait of Hormuz, though nothing has been signed yet and any agreement would require final sign-off from President Donald Trump and Iran’s Supreme Leader.

The officials said the deal would lead to Iran reaching an agreement to dispose of its enriched uranium stockpile, though how that would be done remains under discussion.

One senior official told reporters an agreement would not be signed on Sunday, saying the Iranian system did not move fast enough.

The official said Washington understood Iran’s Supreme Leader Ayatollah Mojtaba Khamenei had endorsed the broad template of the deal. There was no immediate confirmation from Iran or elaboration on what an “in principle” agreement meant.

Negotiating the details of the nuclear measures would take more time, he said. He pushed back on suggestions that Iran has not accepted disposing of its stockpiled enriched uranium. “It’s a question about how,” the official said, adding “there are a number of practical considerations.

Earlier, Trump said he told his negotiators not to rush into a deal with Iran, arguing that the negotiations represent the “exact opposite” of the 2015 Iran nuclear deal, which he described on social media as “one of the worst deals ever made by our Country”.

“Our relationship with Iran is becoming a much more professional and productive one,” Trump said on Truth Social. “They must understand, however, that they cannot develop or procure a Nuclear Weapon or Bomb.”

Trump thanked “all of the countries of the Middle East for their support and cooperation”.

In a later post on his Truth Social network, Trump criticised former president Barack Obama and said: “If I make a deal with Iran, it will be a good and proper one, not like the one made by Obama, which gave Iran massive amounts of CASH, and a clear and open path to a Nuclear Weapon. Our deal is the exact opposite, but nobody has seen it, or knows what it is. It isn’t even fully negotiated yet.”

Earlier, he said he had concluded a “very good call” with leaders of several majority-Muslim nations, including Crown Prince Mohammed bin Salman al Saud of Saudi Arabia, President Mohamed bin Zayed Al Nahyan of the UAE, Prime Minister Mohammed bin Abdulrahman bin Jassim Al Thani of Qatar, Field Marshal Asim Munir of Pakistan, President Recep Tayyip Erdoğan of Turkiye, and President Abdel Fattah el-Sisi of Egypt.

Trump added that he also spoke with Prime Minister Benjamin Netanyahu of Israel, a conversation that he said “went very well”, and insisted the agreement would ensure the Strait of Hormuz will be opened.

Will Netanyahu complicate the deal?

In a statement posted on X on Sunday, Netanyahu said he spoke with Trump about the memorandum of understanding to reopen the Strait of Hormuz and the upcoming negotiations toward a final agreement on Iran’s nuclear program.

“I expressed my deep appreciation to President Trump for his unwavering commitment to Israel’s security, including during Operation Roaring Lion and Epic Fury, when American and Israeli forces fought shoulder to shoulder against the Iranian threat,” Netanyahu wrote.

Netanyahu said he and Trump agreed that any final agreement with Iran must eliminate the nuclear danger, which Netanyahu said means “dismantling Iran’s nuclear enrichment sites and removing its enriched nuclear material from its territory”. Trump also reaffirmed Israel’s right to defend itself against threats on every front, including Lebanon, Netanyahu said.

In a separate post on X, Netanyahu shared an image of himself standing back to back with Trump, with the caption: “Iran will never have a bomb.”

The Israeli military said in a statement that Chief of the General Staff Eyal Zamir has approved operational plans for continued combat in the Northern Command region on the border with Lebanon. “The IDF continues to monitor regional developments, and is prepared to resume intense combat operations immediately and to further weaken the Iranian terror regime and its capabilities,”

Fewer than 24 hours after optimism emerged around a possible Iran-U.S. memorandum, worries are already surfacing, Al Jazeera correspondent Ali Hashem reported, citing a well-informed Iranian source.

According to the source, there are signs of US retreat on two central issues – the mechanism for unfreezing Iranian assets, and the scope of a ceasefire in Lebanon. The source said the memorandum includes a Lebanon ceasefire framework, but Israel is reportedly uncomfortable with the arrangement and is pushing Washington to include language allowing it to carry out military operations in Lebanon under the justification of responding to “any threat”. Iran is rejecting that formulation and insisting on a sustainable and lasting ceasefire.

Tehran has informed all mediators, including Pakistan, that it will not sign the memorandum unless all clauses are fully agreed and guaranteed, Hashem reported.

Iran’s semi-official Tasnim news agency, which is close to the Islamic Revolutionary Guard Corps (IRGC), said US obstruction of some clauses of the agreement, including the issue of releasing Iran’s blocked assets, still continues. “Accordingly, there is still a possibility that the agreement may be canceled,” Tasnim reported.

Tasnim also said that under the potential memorandum of understanding, the number of vessels transiting the Strait of Hormuz would return to pre-war levels within weeks. The U.S. naval blockade on Iranian ports must be completely lifted within 30 days, according to the potential memorandum, Tasnim said, adding that at least part of Iran’s frozen funds must be released in the first phase of the agreement. The potential deal also includes an end to the war on all fronts, including in Lebanon.

A senior Iranian source earlier told Reuters that if Iran’s Supreme National Security Council approved the memorandum, it would be forwarded to Supreme Leader Ayatollah Mojtaba Khamenei for final ratification.

Omani and Iranian officials held a meeting to discuss principles governing freedom of navigation through the Strait of Hormuz in accordance with international law, the Omani news agency reported on Sunday.

A military adviser to Iran’s Supreme Leader said on Sunday that managing the Strait of Hormuz was Tehran’s “legal right” to ensure national security. Iranian news agencies reported that Mohsen Rezaei, an adviser to Supreme Leader Ayatollah Ali Khamenei, said Iran’s management of the waterway “ends 50 years of insecurity in the Persian Gulf.”

“Iranians have been saying they are open to diplomatic engagement,” said Al Jazeera correspondent Resul Serdar, reporting from Tehran. “However, each time that they are exchanging proposals and messages, the United States is coming up with new and excessive demands and also changing its position.”

Alan Fisher, Al Jazeera senior correspondent in Washington said: “The President has repeatedly claimed that Tehran has agreed to various concessions, only for Iranian officials to deny them. Many argue Trump’s calculus shifted over the last 24 hours following sharp blowback from his own base, with critics warning that a weak deal would make the entire military campaign a waste of time.”

Qatar University Assistant Professor Abdullah Bandar Al-Otaibi said that Netanyahu’s statements serve as a warning. “Netanyahu is signalling that if this diplomatic framework fails to meet Israel’s standards, Israel is fully prepared to resume and expand military operations independently,” he said.

Abbas Aslani, a senior research fellow at the Center for Middle East Strategic Studies said: “While Netanyahu may not openly defy the Trump administration, Israel will likely use secondary fronts, such as Lebanon, to complicate the implementation process and provoke a reaction, hoping to force Washington to abandon the talks.”