Iran will free an American on Saturday, believed to be one of three hikers detained over a year ago, an official told reporter.
In a brief message, the Ministry of Culture and Islamic Guidance said: "Freedom of one of the American detainees on Saturday 20th of (Iranian month of) Shahrivar at 9:00 am (0430 GMT) at Hotel Esteghlal" in the capital Tehran.
A ministry official contacted by reporter refused to reveal the identity of the detainee, only saying that the release ceremony would be overseen by one of the vice presidents of Iran.
The ministry usually uses text messages to inform the media or invite journalists to events.
Iran is currently holding three U.S. hikers in custody after they strayed into the country from across the border with Iraq. They were arrested on July 31, 2009.
Shane Bauer, 27, Sarah Shourd, 31, and Josh Fattal, 27 have been accused by Iranian authorities of spying and of illegally entering Iran.
The three insist they entered the Islamic republic by mistake after being lost during a hike in Iraqi Kurdistan, while U.S. authorities say they are innocent and should be released immediately.
Several top U.S. officials, including President Barack Obama and Secretary of State Hillary Clinton, Nobel Prize winners and international rights groups have repeatedly urged Iran to release the three hikers.
Last month, Iran's Intelligence Minister Heydar Moslehi said an investigation into the three hikers was nearing its completion.
"The investigation into these three persons is close to being completed and when completed the results will be announced," Moslehi said.
The mother of Shourd, Nora Shourd, had told reporter in August that she was informed her daughter was still being held in solitary confinement. She said that her daughter has a pre-cancerous cervical condition, a lump in her breast and suffers from depression.
Shourd said she had received an unexpected call from her daughter complaining that she was still in solitary confinement and had been denied medical care for five months.
She said Sarah's case amounted to psychological torture based on her solitary confinement and denial of medical care. In May, Iran had allowed the mothers of the trio to visit them.
On the eve of the one-year anniversary of the arrest of the three, Obama had issued a plea for their immediate release, saying they had never worked for the U.S. government and committed "absolutely no crime."
Obama said the trio were "simply open-minded and adventurous young people who represent the best of America, and of the human spirit."
They have "never had any quarrel with the government of Iran, and have great respect for the Iranian people," the U.S. president said. "I call on the Iranian government to immediately release Sarah, Shane and Josh," he said, adding that their "unjust detention has nothing to do with the issues that continue to divide the United States and the international community from the Iranian government."
Iran and Western powers, led by the United States, are at loggerheads over Tehran's nuclear program. The West suspects Iran is masking a weapons drive under the guise of what Tehran says is a civilian atomic program.