The Americans have been jailed for more than two years as accused spies. The delegation arrived Monday at Dulles Airport following a meeting Saturday with Iranian President Mahmoud Ahmadinejad.
The group had hoped to bring home Americans Shane Bauer and Josh Fattal, who say they were hiking in northern Iraq's Kurdish region and accidentally strayed into Iran.
Delegation members believe the two will be released in a matter of days. They say the Iranians are hopeful that the U.S. will reciprocate and review the cases of Iranians jailed in the U.S.