TEHRAN, Iran (AFP) — The United States (US) and Iran are to launch talks on a final settlement to their conflict on Friday in Switzerland, officials said, as news that the Strait of Hormuz will reopen sent world oil prices tumbling.

Negotiations over a final deal are to start immediately after a deal signing ceremony and continue during a 60-day window, leading to decisions on the fate of Iran’s nuclear programme and a plan for the lifting of international economic sanctions.

Optimism that the war triggered by the February 28 US-Israeli strikes on Tehran might be coming to an end was dented, however, by fresh Israeli strikes on south Lebanon.

Iran’s central military command, Khatam al-Anbiya, warned that Israel should “await a harsh response” to the strikes, which Lebanon’s state news agency said targeted two vehicles in the town of Mayfadoun and another in nearby Shukeen, near the town of Nabatieh in southern Lebanon, killing four.

The Israeli military said it conducted a strike after it “identified a suspicious vehicle” near where its soldiers were operating and that its forces intercepted several rockets and carried out an air strike against a launcher.

Friday’s signing ceremony will take place at Switzerland’s mountainside Burgenstock resort, perched high above Lake Lucerne, the Swiss foreign ministry said.

According to a senior US official, speaking on condition of anonymity, the framework agreement has already been signed electronically by US President Donald Trump, Vice President JD Vance, Iran’s deputy foreign minister Majid Takht-Ravanchi and top negotiator Mohammad Bagher Ghalibaf.

“Likely on Friday… a new round of negotiations between Iran and the United States to reach a final agreement will begin,” Iranian Foreign Minister Abbas Araghchi said. “In the final agreement, decisions will be made on the nuclear issues and the lifting of sanctions.”

Ghalibaf will attend the signing and the US side will be represented by Vance, who said Trump might also attend.

The developments came after Trump said an Iranian blockade on the crucial Hormuz strait oil and gas route would be fully lifted by Friday, in a major boost to the global economy.

“Ships are starting to move, many loaded up with oil, out of the Strait of Hormuz,” Trump said Monday.

Optimism over the reopening of Hormuz has sent the price of the international benchmark Brent North Sea crude tumbling under $79 a barrel, a three-month low. The main US oil contract, West Texas Intermediate, fell 5.9 per cent to under $76 a barrel.

The US had, in retaliation for Iran’s action, imposed its own blockade on Iranian ports. But Iranian state television said Iranian tankers had resumed shipping following the deal, as Takht-Ravanchi said the US blockade “has been lifted prior to the formal signing”.

Sporadic episodes of violence since an April ceasefire had threatened a deal, but weeks of indirect negotiations mediated by Pakistan and Qatar built momentum for an interim deal.

Yet a comprehensive agreement on Iran’s nuclear ambitions and Western sanctions remains elusive.

The US and Israel are pressing to strip Iran of its stockpile of highly enriched uranium, said to have been buried by US strikes last year, while Iran has insisted on its right to enrichment.

The agreed framework has however paved the way for talks on those key disputes.

Asked at the G7 in France when the text would be released, Trump said: “It’s a very powerful document, and I want it to be released. So probably pretty soon.”

Iran’s ultraconservative newspaper Vatan-e Emrooz praised the agreement as a “Trump surrender document”.

But Araghchi struck a more cautious note.

“We have a history of broken commitments… we have a history of agreements being torn up. All of this is present in our minds,” he said.

In a flurry of interviews to talk up the deal, Vance said no US taxpayer money would go to Iran under the deal, as Iranian media reported $12 billion of frozen assets would be released.

Vance told NBC that nuclear inspectors would also be allowed to enter Iran.

Analysts have warned that the parallel conflict in Lebanon between Israel and Iran-backed Hezbollah presents the biggest threat to the diplomatic thaw.

Lebanon was pulled into the war in March when Hezbollah launched rockets at Israel after the killing of Iran’s supreme leader, prompting Israeli strikes and a ground invasion.

That theatre of the conflict could be “the biggest ultimate spoiler” of the coming negotiations, said Ross Harrison, a senior fellow at the Middle East Institute.