Iran confirmed on Thursday that it had signed the agreement with the United States to end the war in the Middle East, as US President Donald Trump had announced earlier.
Iran's official news agency IRNA quoted Foreign Ministry spokesperson Ismail Baqaei as saying: "The drafting of the text of the Islamabad memorandum of understanding has been concluded with the signing of the two presidents. The time has now come to test the implementation of this agreement."
He added that the signing took place electronically, and that holding a formal ceremony "was not really on the table" in Iran's plans.
The Swiss government had initially announced that a signing ceremony would be held on Friday at a luxury hotel on Mount Bürgenstock overlooking Lake Lucerne.
Iran had indicated that the document would be signed by its chief negotiator Mohammad Baqer Qalibaf and US Vice President JD Vance.
Baqaei said: "When the highest officials of the two countries sign the text, the consequences of non-compliance are naturally more severe, and given our previous experience, we preferred" this approach.
The memorandum of understanding, revealed by both sides on Wednesday, stipulates that the United States will suspend its sanctions on the sale of Iranian oil immediately upon signing, and will then lift all its sanctions if a final agreement is reached, at the end of a 60-day negotiating period.
In return, Iran is required to allow the full resumption of maritime navigation through the strategic Strait of Hormuz within 30 days, as the ongoing closure it has imposed casts a shadow over the global economy.
The agreement also provides for discussions on Iran's nuclear programme, and the establishment of a fund for the reconstruction and economic development of Iran.