The Iranian delegation participating in talks with the United States has left Switzerland and is returning to Tehran after 18 hours of intense negotiations.
The delegation, led by chief negotiator Mohammad Bayer Ghalibaf, left the building where the talks took place after about 18 hours of intensive consultations and contacts.
Meanwhile, Iran says only a "brief discussion" took place with the United States over its nuclear program, insisting that substantive negotiations on the issue have not yet begun.

"One of the issues raised by the American delegation was the presentation of its positions on the nuclear issue," said Iranian Foreign Ministry spokesman Esmail Baghai.
"There was a very brief discussion on the nuclear issue, but no details were discussed and it cannot be said that negotiations on the nuclear program have begun," he added.
After the Iranian delegation left the talks in Burgenstock, Switzerland, delegations from the United States, Qatar and Pakistan remain in place for the time being, although they are expected to leave soon.
The delegations will leave behind technical teams, which will continue discussions throughout the week.