Iran’s top negotiator Mohammad Ghalibaf also says an agreement reached with the US to release $12bn in frozen assets.

Iran says technical talks in Switzerland with the United States and mediators have concluded successfully, paving the way for the next phase of negotiations aimed at ending their more than 100-day war.

Deputy Foreign Minister Kazem Gharibabadi, who led Iran’s technical negotiating team, said the four-party talks concluded with an agreement on arrangements for future negotiations, including working groups and implementation mechanisms, Iran’s official IRNA news agency reported on Tuesday.

Gharibabadi said the discussions followed a high-level committee meeting held on Sunday to monitor the implementation of the Islamabad Memorandum of Understanding, a framework agreement signed virtually by the US and Iranian presidents on June 17 to end the war.

“Technical discussions were held to determine the implementation mechanisms of the memorandum of understanding and the statement issued at the conclusion of the high-level meeting, and the necessary understandings were reached,” he said.

Earlier, Iran’s top negotiator Mohammad Ghalibaf said an agreement has been reached with the US to release $12bn in frozen Iranian assets.

US President Donald Trump says those funds will be used to buy US produce.

“We’re doing very well in terms of negotiating a fair and reasonable deal,” Trump said from the Oval Office. “Money that’s being unfrozen is going to be used to buy food, and the food is going to be bought exclusively through the United States from our farmers, and corn, soybeans, all of the things they need are going to be bought from our farmers,” he said.

The US Department of the Treasury has also announced a 60-day waiver allowing Iran to sell its oil and petrochemical products.

“What has happened over the last 24-48 hours has been hugely significant because it is a reversal of US policy – sanctions on the Iranian oil industry,” said Alan Fisher, reporting from Washington, DC.

“For many, many years, the Iranians managed to sell the oil despite the sanctions, but at a huge discount. That’s because countries were concerned about being on the wrong side of US sanctions,” Fisher said.

“Now, Iran can sell the oil at full price, which will bring hundreds of millions of dollars into the Iranian economy. This is a huge change, but the Americans insist the Iranians still have to meet those benchmarks if other sanctions are to be lifted,” he added.

Meanwhile, on the Strait of Hormuz, a key waterway through which about a fifth of global energy exports transit, Tehran has agreed to establish a line of communication with the US to ensure safe passage.

But Ghalibaf, who is also Iran’s parliament speaker, said the status quo around the waterway would not return to what it was before the conflict.

“Everybody should know that the administration of the Strait will never return to the way it was before the war; of course, we will fully comply with international law,” the Iranian top negotiator said while on his way back from talks in Switzerland.

Tehran enforced control over the narrow strait by attacking, or threatening to attack, vessels trying to transit, as part of its response to the US-Israel war on Iran.