US Vice President JD Vance on Thursday announced the official start of the next phase of negotiations with Iran following the conclusion of a framework agreement aimed at ending hostilities between the two countries.
The 60-day period set out in the memorandum of understanding had "officially started today," Vance told reporters at the White House.
During that time, negotiators are expected to tackle some of the most contentious and unresolved issues that were left open in the initial accord. These include key questions surrounding Iran's nuclear programme and the future of its stockpiles of highly enriched uranium.
The 60-day deadline to achieve a final settlement can be extended if both sides agree.
According to Pakistan, which mediated the agreement, the framework accord entered into force with "immediate effect" overnight into Thursday after it was signed by both parties.
Vance said the agreement had already been signed electronically.
"We're going to start the 60-day clock today," he said.
Timing of Vance trip to Switzerland unclear
The agreement was initially expected to be formally signed at an in-person ceremony on Friday in Switzerland attended by Vance, with the next stage of talks also kicking off. The text has already been signed electronically by both sides.
US President Donald Trump subsequently signed a paper copy on Wednesday evening at the Palace of Versailles outside Paris, where French President Emmanuel Macron hosted him following the conclusion of the G7 summit.
Macron, seated beside Trump as he signed the document, told him: "Great job."
Vance, who has taken on the role of Trump's lead negotiator, said he plans to travel to Switzerland for talks with Iran, although the timing has yet to be finalized.
"We're trying to figure out exactly when that's going to happen," he said, adding that the trip could take place as soon as this weekend depending on if arrangements could be made with Iran.
What the agreement says
The United States and Iran reached the 14-point framework agreement on Sunday after weeks of negotiations.
According to a senior US administration official speaking on condition of anonymity, the accord provides for an "immediate and permanent termination of military operations on all fronts, including in Lebanon."
However, several questions remain unresolved, including whether Israel and the Iran-backed Hezbollah militia in Lebanon will adhere to the agreement and what would happen if fighting between the two sides continues.
The deal does not include a withdrawal of Israeli troops from Lebanon, a demand that had been backed by Iran.
Another potential source of friction is Iran's proposed transit fee for shipping through the Strait of Hormuz. Under the framework agreement, Tehran has agreed not to impose any such charge during the 60-day negotiation period. Any arrangement beyond that is to be negotiated separately between Iran and Oman.
Washington has repeatedly described any toll on shipping through the strategic waterway as unacceptable.
Key issues surrounding Iran's nuclear programme are also due to be addressed during the negotiations. As a minimum confidence-building measure, highly enriched uranium already in Iran is to be diluted on site under the supervision of the International Atomic Energy Agency (IAEA), according to a US official.
