Sarah Shourd is back in the U.S. after being freed from an Iranian prison in September. Iranian authorities said they freed Shourd as a humanitarian gesture because of unspecified health concerns, though she has since said her health is fine.
Iran warned that it will seize the $500,000 bail posted by Shourd if she does not return for trial. The 32-year-old Oakland woman has not disclosed any plans to return to Iran.
Her fiance, Shane Bauer and their friend Josh Fattal remain incarcerated in Iran.
The three contend they were hiking in northern Iraq and inadvertently crossed an unmarked border into Iran.
They are facing espionage charges.
The Associated Press contributed to this report.