The Iranian delegation left Switzerland for Tehran on Monday after the first round of talks with the United States ended, Foreign Minister Abbas Araghchi said.
Araghchi said the delegation, led by Iranian parliament speaker Mohammad Bagher Ghalibaf, left after about 18 hours of talks and consultations.
Mediators Qatar and Pakistan said the first round produced a roadmap toward a final agreement within 60 days.
A joint statement said technical discussions would continue this week at the Buergenstock resort in Switzerland.
The sides also agreed on a mechanism to end fighting in Lebanon, according to the statement.
They also set up a communication channel to help secure safe passage for commercial vessels through the Strait of Hormuz.
Araghchi said Tehran had secured waivers for oil and petrochemical exports. He also cited the release of some frozen assets and a reconstruction and development plan for Iran.
The talks followed a memorandum of understanding reached last week to extend a fragile ceasefire for at least another 60 days. The negotiations came under pressure after Iran said it had again closed the Strait of Hormuz.
US President Donald Trump warned Iran before the talks that “you won’t have a country” if it tried to shut the waterway again.
Read: Lake Lucerne Summit Sets 60-Day U.S.-Iran Roadmap
A US diplomat involved in the talks denied reports that the Iranian delegation had walked out. The diplomat said the sides continued discussions on the Strait, Lebanon, nuclear issues and implementation of the memorandum.
