The Washington Post on Monday denounced the conviction in Iran of the newspaper's U.S.-born Tehran correspondent in an espionage case as an "outrageous injustice" and urged Iranian leaders to overturn it.
Jason Rezaian, who was arrested in July 2014, had 20 days to appeal the verdict, the Iranian news service ISNA said, citing an Iranian judiciary spokesman.
The case is a sensitive issue in Washington's contentious relationship with Tehran and it played out as the United States and other major powers forged a deal in July with Iran to curb its nuclear program in return for relief from sanctions.
Washington Post Executive Editor Martin Baron said the verdict against Rezaian was indefensible and that no sentence had been announced.
"The guilty verdict announced by Iran in the trial of the Washington Post’s Jason Rezaian represents an outrageous injustice," Baron said.
"Iran has behaved unconscionably throughout this case ... The contemptible end to this 'judicial process' leaves Iran's senior leaders with an obligation to right this grievous wrong."
Post officials said Rezaian had been used as a bargaining chip. The newspaper's foreign editor, Douglas Jehl, told Fox News that Rezaian's wife, mother and lawyer had gone to court in Tehran seeking an explanation of the court's action but were turned away after being told no translators were available.
Iran accused Rezaian, 39, of collecting confidential information and giving it to hostile governments, writing a letter to U.S. President Barack Obama and acting against national security.
The Post and his family denounced the charges against Rezaian, who holds both U.S. and Iranian citizenship, as absurd.
A watchdog group, the International Campaign for Human Rights in Iran, said Rezaian's trial, which concluded in August, was a "judicial farce" and challenged Iranian President Hassan Rouhani to correct it.
"Rouhani's unwillingness to address this miscarriage of justice calls into question his stated commitment to ensure Iran is a country ruled by law," said Hadi Ghaemi, the group's executive director.
A senior Iranian official dismissed in August speculation that Iran was considering a prisoner exchange with the United States. Iran holds other U.S. citizens, and said at the time that the United States holds some 16 Iranians for bypassing sanctions and around 60 prisoners for other crimes.
The other U.S. citizens detained in Iran are Christian pastor Saeed Abedini and Amir Hekmati, a former sergeant in the U.S. Marine Corps. Robert Levinson, a private investigator, disappeared in Iran in 2007.