The case of a US-Iranian correspondent for the Washington Post who has been detained since July is to go before the Islamic republic's revolutionary court, Tehran's prosecutor general said on Wednesday.
"With the investigation closed, the charge sheet has been drawn up and the case of Jason Rezaian has been sent to the revolutionary court," said Abbas Jafari-Dolatabadi, quoted by Fars news agency, without giving details or any date.
Iran's revolutionary court normally handles cases involving political or national security crimes.
Rezaian's mother, who is in Iran, has been able to see him twice, according to the prosecutor general.
Earlier on Wednesday, Iran's Foreign Minister Mohammad Javad Zarif told reporters in Geneva ahead of talks with US Secretary of State John Kerry that Tehran hopes the case can be resolved, but stressed it was a matter for the courts.
Rezaian, a dual national and the Washington Post's bureau chief in Tehran, was charged in early December after a lengthy court appearance.
But the specific accusations against him remain unclear, according to the Post, and it is not known when he will next appear in court.
"The government is doing its best to be of assistance. This is a judicial matter," Zarif said. "We will have to wait for the judiciary to move forward, but we try to provide all we can in assistance."
Rezaian, 38, was arrested with his wife, Yeganeh Salehi, who was freed on bail in October. In December, Iranian authorities said Rezaian's detention would be extended for up to 60 days.
"He's still not 100 percent sure" what the accusations are, Rezaian's brother, Ali Rezaian, told the Washington Post this week, adding he is only aware of five charges relating to alleged "activities outside the bounds of journalism".
Mary Rezaian, the mother, has said she was concerned by her son's appearance when they met in Tehran's Evin jail.
"He looked very different," she told the Post. "He had lost 40 pounds (18 kilos)."
She said her son was also suffering from health problems, including an eye infection and back pain from having to sleep on a floor.
Rezaian is no longer being held in solitary confinement and is allowed regular exercise -- including outdoor activity -- but he has still not been given access to a lawyer, his family said.
Kerry has said he was "distressed" at how Rezaian's case has been handled, and has called on the Iranian authorities to drop the charges and release him immediately.