Donald Trump may decide to release a preliminary deal to end the war with Iran before Friday, US Vice-President JD Vance says, after the US president said the agreement had already been signed.

Vance has described the memorandum of understanding (MOU) between the US and Iran as "about a page and a half" and a "very general" document.

Senior US officials have also begun giving some details about the deal, briefing that the Strait of Hormuz would re-open on Friday - the same day the deal is formally inked in Geneva.

Iran's Foreign Minister Seyed Abbas Araghchi confirmed a new round of negotiations on reaching a final peace deal with the US would begin in Switzerland the same day.

It comes as Trump attends the G7 summit in France, which will on Tuesday host a special session about Iran attended by the leaders of Egypt, Qatar and the United Arab Emirates.

On Monday, during talks with French President Emmanuel Macron, Trump said: "I am very happy to say it's signed, the deal is all signed", referring to the preliminary agreement.

US officials said it had been signed electronically by Trump, Vance and Iranian parliamentary speaker Mohammad Bagher Ghalibaf.

Technical talks on Iran's nuclear programme are expected to begin this week, the officials said, while any sanctions relief or release of assets will depend on Iran meeting commitments under the deal.

Vance told NBC News that nuclear inspectors would "absolutely" be allowed back into Iran as part of the deal.

"One of the core parts of the agreement is that the [International Atomic Energy Agency] and the United States are going to help Iran destroy the highly enriched stockpile - and that's something that's spelled out very clearly."

While Trump had earlier suggested that details of the agreement were set to be published "pretty soon" after Friday's ceremony, Vance told Fox News the US president might decide to release the agreement with Tehran before then.

Vance earlier told CNN's Jake Tapper that the memorandum of understanding (MOU) was a very general document, adding that a lot of the details would be worked out during future negotiations.

"On a number of issues, we are going to have to figure this stuff out during the technical negotiation phase, but what the MOU does is set up a framework whereby the Iranians get the benefits of the bargain by meeting their obligations under the bargain," he said.

In "paragraph one" of the document it is outlined that Iran will commit itself to "regional peace and stability", Vance said, which he added included stopping the funding of "terrorist organisations".

"Most importantly, they're going to have a verifiable commitment to not building a nuclear weapon," Vance said.

G7 allies will be eager to discuss Iran with Trump, with the UK and France having led plans for a defensive mission to protect vessels in the Strait of Hormuz.

Trump said he did not believe the US would "need much help" in ensuring the free passage of shipping but added he did not think it was "a bad idea to have a ship or two" from other countries based in the strategic waterway.

The deal will extend a ceasefire for another 60 days, during which the sides will negotiate details of a final agreement.

Announcing the breakthrough on Sunday, Pakistan's Prime Minister Shehbaz Sharif, whose nation had been mediating, said it included "the immediate and permanent termination of military operations on all fronts, including in Lebanon".

The US officials said that while Lebanon was covered by the ceasefire framework, the withdrawal of Israeli forces from Lebanese territory was not a condition of the deal. Israel would retain the right to self defence, they added.

Israeli Prime Minister Benjamin Netanyahu said on Monday evening that Israeli forces would remain in security zones in Lebanon, Syria and Gaza "as long as necessary", and retain the freedom to act against attacks.

He also told a news conference Iran would not be allowed to obtain nuclear weapons, with or without a deal.

Netanyahu was speaking after Lebanese media reported a deadly Israeli strike on a car in the south - the first since the peace deal was announced. Hezbollah said it had fired missiles and drones at Israeli forces in return.

The Israel Defense Forces later confirmed four people had been killed in strikes it said had been targeting terrorists.

Araghchi warned that Iran would view any Israeli attack on Lebanon or continued presence in Lebanese territory from now on as a violation of the interim agreement with the US.

"In our view, the two parties to this memorandum are the US and Israel on one size, and Iran and Hezbollah on the other," he said.