Iran will begin trying three American hikers on espionage charges on November 6, their lawyer has revealed.
The US secretary of state Hillary Clinton immediately said there was no basis for a trial.
Two of the three hikers, Josh Fattal and Shane Bauer, have been held in a Tehran jail for more than a year, while female companion Sarah Shourd was released on bail of about $500,000 dollars last month.
"It is true that on November 6 their trial will start at 10 am (6.30am GMT)," the lawyer Masoud Shafii said, adding that judge Abolqasem Salavati would preside over proceedings.
Mr Salavati has overseen a string of trials of defendants charged with anti-Iran or anti-revolution activities, particularly cases connected with huge street protests that followed Iran's controversial 2009 presidential election.
He also presided over the trial of the French academic Clotilde Reiss, who was arrested during the election unrest and later freed after paying a fine of $285,000.
Mr Shafii said he had informed the families of the three hikers of the trial date.
"The three are accused of espionage and illegally entering the country," he said, adding it was up to the family of Ms Shourd, who returned to the United States on her release, to decide whether she should attend the trial or not.
"If she is not present, it will hurt her bail. I cannot request that she be present. It is up to them to decide. I as a lawyer have only informed them of the time of the trial and I will execute my duty to defend the three," he said.
After Ms Shourd's release on bail, a Tehran prosecutor Abbas Jafari Dolatabadi warned that if she did not appear in court, the surety would be "seized" and she would be tried in absentia.
On Tuesday, Mrs Clinton renewed appeals for the release of the two men still in custody on "humanitarian" grounds and said she was aware that their trial had been set for November 6.
"We do not believe that there is any basis whatsoever for them to be put on trial and we regret that they and their families are being subjected to a criminal system that we do not think in any way reflects their actions," she said.
"So it's our continuing request to the Iranian government that, just as they released the young woman, that they release these two young men," Mrs Clinton said, adding "it's unfortunate" the pair had been held for more than a year.
Iranian authorities arrested the three hikers on July 31, 2009 after they strayed across the border from Iraq, and accused them of "spying and illegally entering the country."
The three have denied the charges, insisting that they mistakenly entered Iran after getting lost during a trek in Iraqi Kurdistan.