Iran's foreign ministry said on Monday it would have to see if there are changes in the US position on sanctions, as the two countries negotiate a deal to resolve a decades-long dispute over Iran's nuclear ambitions.
"I regret to inform you that the American side has not yet been willing to clarify this issue," ministry spokesperson Esmaeil Baghaei said in a weekly press conference in Tehran.
"It must be clear to us how the oppressive sanctions against the Iranian people will be lifted, to ensure that past experiences are not repeated," he added.
Oman's Foreign Minister Badr Albusaidi, who has been mediating between Iran and the Trump administration, presented elements of a US proposal for a nuclear deal between Tehran and Washington during a short visit to Tehran on Saturday.
Iranian and US delegations wrapped up a fifth round of talks in Rome last month and, while signs of some limited progress emerged, there are many points of disagreement that are hard to breach, notably the issue of Iran's uranium enrichment.
