The Tehran government on Friday urged the United States to release Iranians held in US jails on sanctions-related issues due to fears about the coronavirus epidemic.
The death toll in Iran from the coronavirus meanwhile rose Zarif to 2,378 on Friday, a jump of 144. Iran is one of the worst-hit countries in the world.
Foreign Minister Mohammad Javad Zarif accused the United States of holding a number of Iranians in its prisons and said that under the circumstances they should be set free.
"US even refuses medical furlough — amid #covid19 — for innocent men jailed in horrific facilities. Release our men," he said on Twitter.
Zarif also referred to a report by The Guardian newspaper about Dr Sirous Asgari, a science professor, who it said was still being held in a crowded facility after being acquitted in November on US federal charges of stealing trade secrets.
"US has taken several Iranian scientists hostage — without charge or on spurious sanctions charges — & not releasing them; even when its OWN courts reject the absurd charges," Zarif said.
On Thursday, the United States blacklisted five Iran- and Iraq-based companies and 15 individuals accused of supporting terrorist groups, its third round of sanctions on Iranian targets in the last two weeks even as Tehran battles the coronavirus outbreak.
Humanitarian supplies are exempt from sanctions Washington reimposed on Tehran after US President Donald Trump abandoned the 2015 international agreement curbing Iran's nuclear programme.
However, broader US sanctions deter many firms from humanitarian trade with Iran.