US Secretary of State John Kerry said Sunday he was "deeply disappointed" by reports that a US journalist jailed in Iran had been charged and denied bail more than four months after his arrest.
Jason Rezaian, a Washington Post bureau chief in Tehran who holds dual US-Iranian citizenship, was charged Saturday after a lengthy court appearance, the Post reports.
But the specific accusations remain unclear, according to the newspaper, and it is not known when he will next appear in court.
Rezaian, 38, was arrested on July 22 with his wife, Yeganeh Salehi, who was freed on bail in October. Last week, Iranian authorities said Rezaian's detention would be extended for up to 60 days.
Kerry said he was "distressed" at how Rezaian's case had been handled, and slammed Iran for flouting the law by denying him access to a lawyer.
"The United States is deeply disappointed and concerned by reports that the Iranian judiciary has charged Washington Post journalist Jason Rezaian with unspecified charges, and that the judge denied his request to be released on bail," Kerry said in a statement.
He called on the Iranian authorities to drop the charges "and release him immediately."
Kerry said denying access to an attorney "is a clear violation of Iran's own laws and international norms."
"I am personally dismayed and disturbed at these reports as I have repeatedly raised Jason's case."
According to the Washington Post, Saturday's court hearing lasted 10 hours and Rezaian appeared alongside a translator who explained the charges to him.
The newspaper said Rezaian signed a document signaling that he understood the charges being brought against him.
Kerry said requests to access Rezaian in prison had been denied, and that his family was concerned for his health.
"We share the concerns of Mr Rezaian's family regarding reports that he is under physical and psychological distress, and is not receiving proper medical care," Kerry said.
It remains unclear why Rezaian, 38, and Salehi were arrested on July 22, though one conservative newspaper in Tehran has accused Rezaian of espionage.
Washington Post Executive Editor Martin Baron said the paper was "dismayed and outraged" at the reports Rezaian had been charged.
"The Iranian government has never explained why Jason was detained or why he has been held for more than four months without access to a lawyer," Baron said in a statement.
"If he has indeed been charged, we know that any fair legal proceeding would quickly determine that any allegations against him are baseless."
Rezaian's detention has attracted considerable attention amid the ongoing talks between Iran and the United States and other world powers over the Islamic republic's disputed nuclear program.