The mothers are on a visit to Iran in hopes of securing the release of their children Sarah Shourd, 31; her boyfriend, Shane Bauer, 27; and their friend Josh Fattal, 27, who were arrested in July along the Iran-Iraq border and have been accused of espionage.
So far, Iranian authorities have given no indication that Shourd, Bauer and Fattal could be freed, or that their mothers would even be allowed to make a face-to-face appeal to top Iranian leaders like President Mahmoud Ahmadinejad or Supreme Leader Ayatollah Ali Khamenei, as they have hoped.
One glimmer of hope came as state TV reported that the American military in Iraq has released two Iranians detained for entering Iraq without a passport. The two Ahmad Barazandeh and Ali Abdolmaleki have been held for seven and two years, respectively, Iran's ambassador to Baghdad was quoted by the report as saying. Iraqi and U.S. officials in Baghdad could not immediately confirm the report.
The TV report made no connection between the release and the case of the three Americans.
But Iran has hinted in the past that it wants to swap the three Americans for Iranians being held by the United States.
On Thursday, U.S. State Department spokesman P.J. Crowley told reporters in Washington, "We're not contemplating any kind of a prisoner swap" for the three Americans.
"But if Iran has questions about any of its citizens and whether we have any information as to their whereabouts, we would be more than happy to receive that diplomatic note and respond to it," he said.
There have been hints of such swaps in a past case. In 2009, U.S. forces in Iraq freed five Iranians who had been detained since 2007 on suspicion of aiding Shiite militants, and their release came several months after Iran freed an Iranian-American journalist, Roxana Saberi, who had been arrested in early 2009 and accused of espionage.
In another possible swap, Iran this month freed a 24-year-old French academic, Clotilde Reiss, arrested 10 months ago in connection to Iran's crackdown on postelection protests. Just before her release, Paris allowed an Iranian detained in France on a U.S. warrant over suspicions of buying technology for Iran's military to return to his homeland. And soon after Reiss' release, France also freed an Iranian imprisoned for the 1991 assassination of a former Iranian prime minister.
Iran says Shourd, Bauer and Fattal were arrested after entering Iran illegally last July. Their relatives say the three were simply hiking in Iraq's scenic and largely peaceful mountainous northern Kurdish region and that if they did cross the border it was accidental.
Anxious to show how well the captives are being treated, authorities arranged for the meeting at the luxury hotel, rather than a visit at the country's notorious Evin prison, reported CBS News correspondent Elizabeth Palmer.
No cameras or media were allowed to cover the meeting, unlike an emotional reunion the day before at the hotel their first since the arrests when the three young Americans and their mothers embraced and sat together for nearly four hours.
The detention of the three Americans has become intertwined with Iran's accusations that the United States is unfairly holding a number of Iranians in custody.
Since their arrest, Iran has been demanding the U.S. free a number of Iranians including several who have been tried and sentenced in the United States for trying to arrange illegal sales to Iran. Also among them is a nuclear scientist, Shahram Amiri, who disappeared during a visit last year to Saudi Arabia, raising speculation he defected to the West.
To underscore the connection, the mothers of the five Iranians released by the Americans in 2009 were brought to the hotel on Friday to meet with the Americans' mothers, Nora Shourd, Cindy Hickey and Laura Fattal.
In the meeting, aired in part on state TV, the Iranian women pointedly said American officials never gave them the chance to see their loved ones while they were held in Iraq. The women also claimed their sons were mistreated in U.S. custody.
The Americans' fate could also be caught up in Iran's brinksmanship with the West over Tehran's disputed nuclear program and a U.S.-led push for harsher sanctions. Just before the American mothers' arrival in Tehran, Washington said it had won support from other major powers for a new set of U.N. Security Council sanctions against Iran over its refusal to stop uranium enrichment.
The three Americans' Iranian lawyer, Masoud Shafii, on Thursday predicted it was "very unlikely" that the jailed Americans would be allowed to return home with their mothers because the case has not yet reached the courts.
But he said in an interview with AP Television News that decisions could be made outside the normal legal framework and that "anything can happen."
Iran granted the women visas to visit their children in what it called an "Islamic humanitarian gesture" and the Americans appealed to them to release the three on the same grounds.
At the trio's meeting with their mothers on Thursday, Josh Fattal told reporters, "We hope we're going home soon, maybe with our mothers."
The meeting was heavily covered by Iran's state-run Press TV, the government's main English-language broadcast arm. Reporters for the foreign media also were allowed their first glimpse of the three Americans.
They appeared healthy, wearing jeans and polo-style shirts. Sarah Shourd wore a maroon-colored head scarf. They described their routines behind bars and the small things that take on major significance: being allowed books, letters from home, the ability for some exercise and the one hour each day they are all together. The last direct contact with their families was a five-minute phone call in March.
Hickey lives in Minnesota, Shourd is from Oakland, California, and Fattal is from suburban Philadelphia.