State television has already shown brief snippets of the interviews with Haleh Esfandiari and Kian Tajbakhsh, where they appear to implicate themselves in alleged US efforts to overthrow Iran's Islamic authorities.
Washington said it was "outraged" and "appalled" by the footage, whose full version will be shown in a programme entitled "In the Name of Democracy" at 9:45 pm (1815 GMT).
Esfandiari and Tajbakhsh have been held in Tehran's Evin prison since their arrest and have been linked by the intelligence ministry to the purported US drive to unseat Iran's rulers under the guise of promoting democracy.
"I am Haleh Esfandiari. One of my roles was to identify speakers," Esfandiari said in Monday's promotional trailer for the programme, dressed in a black Islamic headscarf and coat.
"To divide the people from the government," said Tajbakhsh. An excerpt is spliced in which Esfandiari adds: "In the name of dialogue, of empowering women and in the name of democracy."
However the brevity of the trailer made it difficult to determine firm conclusions from their statements and Wednesday's programme will be closely watched for the full details of the admissions.
Both detainees looked in relatively good health, with Esfandiari seated next to a potted plant, a large white fridge and her spectacles resting on a coffee table.
Tajbakhsh, sporting a neat beard and glasses, sat in a room equipped with a Persian carpet, television, and a large shelf filled with books. He had papers on his lap to which he referred.
State television has touted the programme as "confessions" but the judiciary insisted the statements have no legal validity and their case is not linked to the programme.
"This programme has been made by Iranian state television. The judiciary has already announced it has no legal weight," Intelligence Minister Gholam Hossein Ejeie told the student news agency ISNA.
"This is not an issue of a confession. They are talking as experts, like other experts do in other Iranian television productions," a judiciary source told AFP.
The United States angrily condemned the footage but Iran, which does not recognise dual nationality, has always bluntly told Washington the affair is none of its business.
"We are outraged that the government of the Islamic Republic of Iran would parade two of these American citizens on state-run television on July 16," said State Department spokesman Sean McCormack in a statement.
McCormack said the two were "apparently reading statements made under duress."
Esfandiari, 67, heads the Middle East programme at the Washington-based Woodrow Wilson International Centre for Scholars. She was arrested after returning to Iran late last year to visit her ailing 93-year-old mother.
Based in Iran at the time of his arrest, Tajbakhsh is an urban planning expert who had ties with the Open Society Institute of US billionaire George Soros.
A major focus of the investigation has been the work of the Soros Foundation, accused by Iran of seeking a peaceful revolution similar to the toppling of communism in Eastern Europe.
"The Soros Foundation, soon after the demise of the Soviet Union and Communism, then targeted the Islamic world," Tajbakhsh says in the programme.
Two other US-Iranians face similar charges but were not referred to in the footage.
California-based businessman Ali Shakeri has also been detained. Parnaz Azima, a journalist for Radio Free Europe's Persian arm, is technically at liberty but has had her passport confiscated and cannot leave the country.
The programme will also carry statements from Iranian-Canadian Ramin Jahanbegloo, an intellectual arrested on similar charges and released in 2006.
Güncelleme Tarihi: 18 Temmuz 2007, 16:59