Iran could exchange prisoners with Washington soon if the US shows goodwill, Iranian Foreign Ministry spokesman Nasser Kanaani said on Monday at his weekly press conference.
"Regarding the issue of exchanging prisoners with America ... negotiations are ongoing through mediators ... if the other party shows the same seriousness and goodwill, this can happen in the near future," Mr Kanaani said in a televised weekly news conference.
Currently, three Iranian-American dual citizens are being held in Iranian prisons, Siamak Namazi, Emad Shargi and Morad Tahbaz.
Mr Namazi is a businessman who was sentenced in 2016 to 10 years in prison on charges of spying and co-operating with the US government.
Iran has detained a number of foreigners and dual citizens over the years, accusing them of espionage and various other state security offences.
Often those charged are sentenced following secretive trials in which human rights groups say they have been denied due process.
Critics of Iran have accused the regime of state-sponsored hostage-taking, arbitrarily detaining and jailing dual citizens to use them as political pawns.
Earlier this month, Iran released one Dane and two Austrian-Iranians who had been detained for several years.
Austrian-Iranian citizens Kamran Ghaderi and Massud Mossaheb were released after being held for 2,709 and 1,586 days, respectively.
Iran’s Foreign Ministry on Monday reaffirmed Tehran was not in any talks to conclude an interim or new nuclear agreement with world powers.
The US and Iran denied a report last Thursday that they were nearing an interim deal under which Tehran would curb its nuclear programme in return for sanctions relief.
US and European officials have been searching for ways to curb Tehran's nuclear programme since the breakdown of indirect US-Iran talks on reviving the 2015 nuclear deal involving Iran, Britain, China, France, Germany and Russia.
The latest statements come after Supreme Leader Ayatollah Ali Khamenei said that Iran should co-operate with the UN’s nuclear watchdog, the International Atomic Energy Agency, but added a number of caveats that suggest full co-operation was some way off.
He also said that Iran did not want a nuclear weapon due to its “religious beliefs” but would have built one by now if it desired.
"There is nothing wrong with the agreement (with the West), but the infrastructure of our nuclear industry should not be touched," Mr Khamenei said, according to state media.
Last month, the IAEA said that some outstanding issues, specifically the installation of cameras and the presence of unexplained highly enriched uranium particles at four sites, had been resolved.
Their decision to halt an investigation into the unexplained uranium particles provoked an angry response from Israeli Prime Minister Benjamin Netanyahu, who said the organisation had become “politicised”.
But the IAEA's head, Raphael Grossi, said last week that only “a fraction of what we envisaged” had been achieved in terms of installing cameras and enrichment monitoring equipment at two major sites, Fordow and Natanz.
“What needs to happen now is a sustained and uninterrupted process that leads to all the commitments contained in the Joint Statement being fulfilled without further delay,” he said.
