A US national has been sentenced in Iran to 10 years in prison on spying charges, Iranian officials have said.
The individual, who has not been named, is also a citizen of another country, deputy judiciary chief Gholamhossein Mohseni-Ejeie said on state television.
The US called for the release of "all US citizens unjustly detained in Iran".
Earlier this year, the authorities in Tehran said as many as 70 people they described as spies were serving sentences in the capital's jails.
The identities of only a handful have been made public.
"This person, who was gathering information and was directly guided by America, was sentenced to 10 years in prison, but the sentence can be appealed," Mr Ejeie said on Sunday.
He said the decision was taken by an Iranian court, without giving any further details.
In a statement, the US Department of State did not refer to any specific person but called on Iranian authorities to release all US citizens it is holding "unjustly… so they can return to their families".